Tumor progression locus 2 (TPL2), also known as mitogen-activated protein kinase kinase kinase 8 (MAP3K8) or cancer Osaka thyroid oncogene (Cot), is an important tertiary serine/threonine protein kinase of the MAPK family, which plays important roles in the regulation of cell proliferation, differentiation, and apoptosis3. The gene discussed is MAP3K8; the disease is cancer.