Serine protease inhibitor A3 is a soluble SIRPα ligand that suppresses inflammation and antitumor immunity. Hou Y, Huang L, Jin C, Li X, Chen Y, Sun L, Wang F, Zhang Y, Wang Y, Zou M, et al. Nat Immunol. 2026 Oct 22. PMID: 42918845. Abstract CommentRecommendBookmarkWatch