| Coligation of the cytoplasmic region of PD 1 with the B cell receptor ( BCR ) in IIA1 . 6 transformants inhibited BCR mediated growth retardation , Ca ( 2+ ) mobilization , and tyrosine phosphorylation of effector molecules , including Ig beta , Syk , phospholipase C gamma 2 ( PLC gamma 2 ) , and ERK1 / 2 , whereas phosphorylation of Lyn and Dok was not affected . ^^^ |