REL, also known as c-REL (ENSG00000162924), is a subunit of the Nuclear Factor kB (NF-kB) complex involved in inflammation processes, in liquid tumors (including Hodgkin’s lymphoma, Adult T-cell leukemia/lymphoma, marginal zone lymphoma) and solid tumors (including breast cancer, pancreatic cancer, gastric cancer) [27]. The gene discussed is NFKB1; the disease is breast cancer.