The following mouse strains were used in this study: two mouse models for CHS carrying different mutations in the Lyst gene – beige and souris mice – (46), one mouse model for HPS2 deficient in AP-3 – pearl mice – (20), a Rab27a-deficient mouse model for GS2 – ashen mice – (45), one model for familial hemophagocytic lymphohistiocytosis (FHL) 2 deficient in perforin – PKO mice – (41, 47), and one model for FHL4 deficient in syntaxin-11 – STX-11KO mice – (43, 44). The gene discussed is PRF1; the disease is hereditary hemophagocytic lymphohistiocytosis.