H2AX and Immunodeficiency: Inhibits tumorigenesis [93,125,126]. H2A.X knockout mice exhibit reduced fertility and a decreased number of lymphocytes, resulting in immune deficiencies [149]. Depletion of H2A.X causes neurological disorders [177,183]. Aberrant expression in heart diseases [106,107]. Mediating mitochondrial function [177] and oxidative stress processes [178].