CDK6 and cancer: The common features in several types of cancer, including melanoma, include constitutive CDK (cyclin‐dependent kinases) activation and of cell cycle deregulation.12, 13 In 38% of cancer, there is a deletion of a tumour suppressor and a negative regulator of CDK4, P16INK4a.14 Furthermore, there are CDK4 gene amplification and mutations in germline in melanoma, causing unhindered CDK4 activity and enhanced cell proliferation.15 CDK6 is regulated by cyclin, more specifically by cyclin D protein and CDK inhibitor protein.