Janus kinase 3 (JAK3) is one of the crucial kinases that mediate IL‐2 receptor signaling, the interaction between IL2rg and JAK3 regulates the activity of immune cells, either a mutation in the IL2rg or JAK3 gene can cause immune deficiency, characterized by NK cell deficiency, downregulation of cytokine expression, and inhibition of immune cell proliferation and differentiation.43, 44, 45, 46. This evidence concerns the gene IL2RG and Immunodeficiency.