A diagram of the human PLCG2 gene. Depicts encompassed domains of human PLCG2. R665W and S707Y mutations identified in relapse CLL are harbored within the SH2 domain. PH, Pleckstrin homology. C-2, calcium binding motif; SH2, Src homology 2; SH3, Src homology 3; X-box, phosphatidylinositol-specific phospholipase C X domain; Y-box, phosphatidylinositol-specific phospholipase C Y domain.