B cells 1 Class Ia Phosphatidylinositol 3-Kinase 1 EC 2.7.1.- 1 EC 2.7.1.137 1 Germinal Center (GC) reaction Hyper-IgM syndrome 1 Letter 1 mehr ... PIK3R1 1 PIK3R1 protein, human 1 RNA Splice Sites 1 Research Support, Non-U.S. Gov't 1 weniger ...