Cancers, such as chronic lymphocytic leukemia (CLL) [56,225], lung cancer [215], cutaneous T cell lymphoma (CTCL) [226], acute myeloid leukemia [227], and colon cancer [228], are characterized by the downregulation of SAMHD1. The gene discussed is SAMHD1; the disease is primary cutaneous T-cell non-Hodgkin lymphoma.