In both rituximab and trastuzumab treatments for follicular lymphoma and metastatic breast cancer respectively, polymorphism in both CD16 (i.e. FcγRIIIa-158V/F) and CD32 (i.e. FcγRIIa -131H/R) were shown to correlate with clinical responses1, 11. Here, FCGR2B is linked to follicular lymphoma.