CDK4 and melanoma: Four genes respondent for four types of inherited melanoma have been identified - cutaneous malignant melanoma 1 (CMM1) on chromosome 1p36, cutaneous malignant melanoma 2 (CMM2) gene CDKN2A on chromosome 9p21, cutaneous malignant melanoma 3 (CMM3) gene CDK4 on 12q14 and cutaneous malignant melanoma 4 CMM4 on chromosome 1p22 [33-37].