EXHIBIT
      D

    


    FORM
      OF
      LOCK-UP AGREEMENT

    


    July
      __,
      2008

    


    Each
      Purchaser referenced below:

    


    
      	 	
              Re:

            	
              Securities
                Purchase Agreement, dated as of July __, 2008 (the “Purchase
                Agreement”),
                between GenSpera, Inc., a Delaware corporation (the “Company”)
                and the purchasers signatory thereto (each, a “Purchaser”
                and, collectively, the “Purchasers”)

            


    

     

    Ladies
      and Gentlemen:

     

    Defined
      terms not otherwise defined in this letter agreement (the “Letter
      Agreement”)
      shall
      have the meanings set forth in the Purchase Agreement. Pursuant to Section
      2.2(a) of the Purchase Agreement and in satisfaction of a condition of the
      Company’s obligations under the Purchase Agreement, the undersigned irrevocably
      agrees with the Company that, from the date hereof until the 12 month
      anniversary of the Effective Date (such period, the “Restriction
      Period”),
      the
      undersigned will not offer, sell, contract to sell, hypothecate, pledge or
      otherwise dispose of (or enter into any transaction which is designed to, or
      might reasonably be expected to, result in the disposition (whether by actual
      disposition or effective economic disposition due to cash settlement or
      otherwise) by the undersigned or any Affiliate of the undersigned or any person
      in privity with the undersigned or any Affiliate of the undersigned), directly
      or indirectly, including the filing (or participation in the filing) of a
      registration statement with the Commission in respect of, or establish or
      increase a put equivalent position or liquidate or decrease a call equivalent
      position within the meaning of Section 16 of the Exchange Act with respect
      to,
      any shares of Common Stock or Common Stock Equivalents beneficially owned,
      held
      or hereafter acquired by the undersigned (the “Securities”).
      Beneficial
      ownership shall be calculated in accordance with Section 13(d) of the Exchange
      Act. In order to enforce this covenant, at such time as the Company appoints
      a
      transfer agent for the securities of the Company, the Company shall notify
      such
      transfer agent to immediately impose irrevocable stop-transfer instructions
      preventing such transfer agent from effecting any actions in violation of this
      Letter Agreement.

    


    The
      undersigned acknowledges that the execution, delivery and performance of this
      Letter Agreement is a material inducement to each Purchaser to complete the
      transactions contemplated by the Purchase Agreement and that each Purchaser
      (which shall be a third party beneficiary of this Letter Agreement) and the
      Company shall be entitled to specific performance of the undersigned’s
      obligations hereunder. The undersigned hereby represents that the undersigned
      has the power and authority to execute, deliver and perform this Letter
      Agreement, that the undersigned has received adequate consideration therefor
      and
      that the undersigned will indirectly benefit from the closing of the
      transactions contemplated by the Purchase Agreement. 

     

    
      
         

      

      
         

        
          

        

      

      
         

      

    

     

    This
      Letter Agreement may not be amended or otherwise modified in any respect without
      the written consent of each of the Company, each Purchaser and the undersigned.
      This Letter Agreement shall be construed and enforced in accordance with the
      laws of the State of New York without regard to the principles of conflict
      of
      laws. The undersigned hereby irrevocably submits to the exclusive jurisdiction
      of the United States District Court sitting in the Southern District of New
      York
      and the courts of the State of New York located in Manhattan, for the purposes
      of any suit, action or proceeding arising out of or relating to this Letter
      Agreement, and hereby waives, and agrees not to assert in any such suit, action
      or proceeding, any claim that (i) it is not personally subject to the
      jurisdiction of such court, (ii) the suit, action or proceeding is brought
      in an
      inconvenient forum, or (iii) the venue of the suit, action or proceeding is
      improper. The undersigned hereby irrevocably waives personal service of process
      and consents to process being served in any such suit, action or proceeding
      by
      receiving a copy thereof sent to the Company at the address in effect for
      notices to it under the Purchase Agreement and agrees that such service shall
      constitute good and sufficient service of process and notice thereof. The
      undersigned hereby waives any right to a trial by jury. Nothing contained herein
      shall be deemed to limit in any way any right to serve process in any manner
      permitted by law. The undersigned agrees and understands that this Letter
      Agreement does not intend to create any relationship between the undersigned
      and
      each Purchaser and that each Purchaser is not entitled to cast any votes on
      the
      matters herein contemplated and that no issuance or sale of the Securities
      is
      created or intended by virtue of this Letter Agreement.

     

    By
      its
      signature below, the Company hereby acknowledges and agrees that, reflecting
      this Letter Agreement, upon the appointment of a transfer agent for the Company,
      it shall immediately notify such transfer agent to place an irrevocable stop
      transfer instruction on all Securities beneficially owned by the undersigned
      until the end of the Restriction Period. This Letter Agreement shall be binding
      on successors and assigns of the undersigned with respect to the Securities
      and
      any such successor or assign shall enter into a similar agreement for the
      benefit of the Purchasers.

    


    ***
      SIGNATURE PAGE FOLLOWS***


    
      
         

      

      
        2

        
          

        

      

      
         

      

    

    


    This
      Letter Agreement may be executed in two or more counterparts, all of which
      when
      taken together may be considered one and the same agreement.

    


    
      	
               

            
	
              Signature

            
	 
	
               

            
	
              Print
                Name

            
	 
	
               

            
	
              Position
                in Company

            
	 
	
              Address
                for Notice:

            
	 
	 
	 
	 
	 
	 
	
              Number
                of shares of Common Stock

            


    

    


    _______________________________________________________________________________________________

    Number
      of
      shares of Common Stock underlying subject to warrants, options, debentures
      or
      other convertible securities

     

    By
      signing below, the Company agrees to enforce the restrictions on transfer set
      forth in this Letter Agreement.

    


    
      	
              GENSPERA,
                INC.

            
	 
	
              By:
                

            	 
	
              Craig
                A. Dionne, Ph.D.

            
	
              President
                and CEO

            


    

    


    
      
         

      

      
        3