ATM belongs to the phosphatidylinositol 3-kinase-like protein kinases (PIKK) family, which includes ATR (ataxia telangiectasia and RAD53 related) and DNA-PKCS (catalytic subunit of the DNA-dependent protein kinase), which all participate in DNA damage signaling [50]. The gene discussed is PRKDC; the disease is Telangiectasia.