**Exhibit 31.2**

 

**CERTIFICATIONS**

 

I,James H. Welch, certify that:

 
| 1.     |   | I have reviewed this  quarterly report on Form 10-Q of Rigel Pharmaceuticals, Inc.;                                                                                                                                                                                                                                                                           |
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| 2.     |   | Based on my knowledge,  this report does not contain any untrue statement of a material fact or omit  to state a material fact necessary to make the statements made, in light of  the circumstances under which such statements were made, not misleading with  respect to the period covered by this report;                                                          |
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| 3.     |   | Based on my knowledge, the  financial statements, and other financial information included in this  report, fairly present in all material respects the financial condition,  results of operations and cash flows of the registrant as of, and for, the  periods presented in this report;                                                                             |
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| 4.     |   | The registrant’s other  certifying officer and I are responsible for establishing and maintaining  disclosure controls and procedures (as defined in Exchange Act  Rules 13a-15(e) and 15d-15(e)) and internal controls over financial  reporting (as defined in Exchange Act Rules 13a-15(f) and  15d-15(f) for the registrant and have: |
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|   |   | a)                                                                                                                                                                                                                                                                                                                                                                      | Designed such disclosure  controls and procedures, or caused such disclosure controls and procedures to  be designed under our supervision, to ensure that material information relating  to the registrant, including its consolidated subsidiaries, is made known to  us by others within those entities, particularly during the period in which  this report is being prepared; |
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|   |   | b)                                                                                                                                                                                                                                                                                                                                                                      | Designed such internal  control over financial reporting, or caused such internal control over  financial reporting to be designed under our supervision, to provide  reasonable assurance regarding the reliability of financial reporting and the  preparation of financial statements for external purposes in accordance with  generally accepted accounting principles; |
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|   |   | c)                                                                                                                                                                                                                                                                                                                                                                      | Evaluated the  effectiveness of the registrant’s disclosure controls and procedures and  presented in this report our conclusions about the effectiveness of the  disclosure controls and procedures, as of the end of the period covered by  this report based on such evaluation; and |
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|   |   | d)                                                                                                                                                                                                                                                                                                                                                                      | Disclosed in this report  any change in the registrant’s internal control over financial reporting that  occurred during the registrant’s most recent fiscal quarter (the registrant’s  fourth quarter in the case of an annual report) that has materially affected,  or is reasonably likely to materially affect, the registrant’s internal  control over financial reporting; and |
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| 5.     |   | The registrant’s other  certifying officer and I have disclosed, based on our most recent evaluation  of internal control over financial reporting, to the registrant’s auditors  and the audit committee of the registrant’s board of directors (or persons  performing the equivalent functions):                                                      |
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|   |   | a)                                                                                                                                                                                                                                                                                                                                                                      | All significant  deficiencies and material weaknesses in the design or operation of internal  control over financial reporting which are reasonably likely to adversely  affect the registrant’s ability to record, process, summarize and report  financial information; and |
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|   |   | b)                                                                                                                                                                                                                                                                                                                                                                      | Any fraud, whether or not  material, that involves management or other employees who have a significant  role in the registrant’s internal control over financial reporting. |

 
| Date: November 8, 2005 |                                                  |
|-----------------------------|-------------------------------------------------------|
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|                        | /s/ JAMES H. WELCH                                    |
|                        | James H. Welch                                        |
|                        | Vice President, Chief Financial Officer and Secretary |