Its importance is underscored by the fact that mutations in the SAMHD1 gene lead to the severe autoimmune disease Aicardi-Goutieres syndrome (AGS) and have been identified as a contributing factor to several cancers, including chronic lymphocytic leukemia (CLL), colon cancer, and lung cancer (Mauney and Hollis, 2018). The gene discussed is SAMHD1; the disease is Aicardi-Goutieres syndrome.