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EXHIBIT 4.1  



	NUMBER	 	SHARES



SEATTLE GENETICS, INC.  



	
INCORPORATED UNDER THE LAWS

OF THE STATE OF DELAWARE	
 	

CUSIP 812578 10 2

SEE REVERSE FOR CERTAIN DEFINITIONS



THIS CERTIFIES THAT  


 
















  


is the record holder of  



FULLY PAID AND NONASSESSABLE SHARES OF COMMON STOCK, $0.001 PAR VALUE, OF 


SEATTLE GENETICS, INC.  


transferable on the books of the Corporation by the holder hereof in person or by holder's duly authorized attorney or legal representative, upon the surrender of this
certificate properly endorsed. This certificate is not valid until countersigned by the Corporation's transfer agent and registrar. 


    
WITNESS the facsimile seal of the Corporation and the facsimile signatures of its duly authorized officers. 


Dated:




	

/s/ H. PERRY FELL	
 	

 	
 	

/s/ CLAY B. SIEGALL
	
CHIEF EXECUTIVE OFFICER AND SECRETARY	
 	

[SEATTLE GENETICS, INC. SEAL]	
 	

PRESIDENT







 
 

SEATTLE GENETICS, INC.    
  


   The Corporation will furnish to any stockholder at the office of the Corporation upon request and without charge, a full statement of the powers, designations,
preferences and relative, participating, optional or other special rights of each class of stock or series thereof and the qualifications, limitations or restrictions of such preferences and/or
rights. 


   The
following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable laws or
regulations: 



	TEN COM	 	—	 	as tenants in common	 	UNIF GIFT MIN ACT—	 	......................... Custodian	 	..............................
	TEN ENT	 	—	 	as tenants by the entireties	 	 	 	(Cust)        	 	(Minor)
	JT TEN	 	—	 	as joint tenants with right of	 	 	 	under Uniform Gifts to Minors
	 	 	 	 	survivorship and not as tenants	 	 	 	Act...........................................................................
	 	 	 	 	in common	 	 	 	   (State)
	 	 	 	 	 	 	UNIF TRF MIN ACT—	 	...................... Custodian (until age ......................)
	 	 	 	 	 	 	 	 	   (Cust)        	 	 
	 	 	 	 	 	 	 	 	................................ under Uniform Transfers
	 	 	 	 	 	 	 	 	     (Minor)        	 	 
	 	 	 	 	 	 	 	 	to Minors Act .....................................................
	 	 	 	 	 	 	 	 	                            (State)	 	 





Additional abbreviations may also be used though not in the above list. 


   For
value received, ________________________________________ hereby sell(s), assign(s) and transfer(s) unto 



	 	 	PLEASE INSERT SOCIAL SECURITY OR OTHER	 	 
	 	 	IDENTIFYING NUMBER OF ASSIGNEE	 	 
	

	 	 	 	 	 
	 ________________________________________



_____________________________________________________________________________________________________ 


PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE(S) 


___________________________________________________________________________________________ 


___________________________________________________________________________________________



______________________________________________________________________________________
Shares 


of the Capital Stock represented by the within Certificate, and do(es) hereby irrevocably constitute and appoint 


__________________________________________________________________________________________ Attorney 


to transfer the said Shares on the books of the within named Corporation with full power of substitution in the premises. 



	Dated ________________________________________________	 	

	

 	
 	



	 	 	NOTICE: The signature to this assignment must correspond with the name as written upon the face of the certificate in every particular, without alteration or enlargement or any change
whatever.
	 	 	Signature must be guaranteed.



Signature(s) Guaranteed: 



	By ______________________________________	 	 
	THE SIGNATURE(S) SHOULD BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION
PROGRAM), PURSUANT TO S.E.C. RULE 17Ad-15.	 	 











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