Some of the lysosomal storage disorders, e.g., Chediak-Higashi syndrome or Hermasky-Pudlak syndrome type 2, are characterized by defective NK cell function and immunodeficiency (Table 1), but the function of the genes mutated in these diseases (LYST and AP3BP1) has not been fully elucidated in NK cell biology. This evidence concerns the gene LYST and immunodeficiency disease.