Mutations and defective expression of the WAF1 p21 tumour-suppressor gene in malignant melanomas.

The WAF1 gene, located on chromosome 6p, encodes a Mr 21 000 protein (p21) that can arrest cell growth by associating with and inhibiting cyclin-dependent kinase complexes that are necessary for cells to exit Gr. Transcriptional activation of WAF1 can be accomplished by increasing levels of p53 prot