ATM and autoimmune disease: To this end, McNally et al. [52] demonstrated that antigen-activated mouse and human T cells in healthy conditions, as well as T cells in the autoimmune disease hemophagocytic lymphohistiocytosis (HLH), exhibit an increased DDR as shown by the elevated levels of classic DDR regulators γH2AX, phospho-p53 (Ser15, Ser46), phospho-ATM (Ser1981), phopsho-CHK2 (T68) and phospho-CHK1 (Ser345).