Immunodeficiency 21, also known as monocytopenia and mycobacterial infection syndrome, is related to nk cell deficiency and pancytopenia. An important gene associated with Immunodeficiency 21 is GATA2 (GATA Binding Protein 2), and among its related pathways/superpathways are Assembly of the pre-replicative complex and Embryonic and Induced Pluripotent Stem Cells and Lineage-specific Markers. The drugs Azacitidine and Tacrolimus have been mentioned in the context of this disorder. Affiliated tissues include bone marrow and myeloid, and related phenotypes are aplastic anemia and immunodeficiency