Immunodeficiency 20, also known as autosomal recessive primary immunodeficiency with defective spontaneous natural killer cell cytotoxicity, is related to common variable immunodeficiency and dermatitis, atopic, 8. An important gene associated with Immunodeficiency 20 is FCGR3A (Fc Gamma Receptor IIIa), and among its related pathways/superpathways are Innate Immune System and Interactions of natural killer cells in pancreatic cancer. Affiliated tissues include nk cells and skin, and related phenotypes are recurrent otitis media and recurrent sinusitis