p.E250K mutation increases PSTPIP1-pyrin binding. A, Cotransfection with pyrin and PSTPIP1 WT or p.E250Q or p.E250K mutants. Immunoprecipitation (IP) was performed with anti-PSTPIP1 and immunoblotted with anti-pyrin and anti-PSTPIP1. B, Cotransfection with PSTPIP1 WT, p.E250Q or p.E250K mutants, and cAbl. Immunoprecipitation with anti-PSTPIP1, phosphorylation was detected with anti-phosphotyrosine. C, Relative band intensity was measured and expressed as n-fold to PSTPIP1 WT. *P < .05.