Such genes are SH2DIA, associated with X-linked lymphoproliferative syndrome (XLP) 1; XIAP, associated with XLP2; RAB27A, associated with Griscelly syndrome type 2; LYST, associated with Chediak–Higashi syndrome; and AP3BI, associated with Hermansky-Pudlak syndrome [22]. The gene discussed is XIAP; the disease is Griscelli disease type 2.