<prompt> Which of the following is considered as a high-risk susceptibility gene for malignant melanoma?CDKN1ACDKN2ACDKN3ACDKN4A  <response>: Ans. B. CDKN2AThe cyclin-dependent kinase CDK inhibitor 2A gene CDKN2A, located on chromosome 9p21, is the best-established high-risk locus for melanoma susceptibility. In melanoma, tumor suppressors that play a protective role against melanoma are mutated. CDKN2A encodes via alternative splicing for two proteins involved in cell cycle regulation: pl6Ink4a and pl4Arf, both act as tumor suppressors through the Rb and p53 cancer pathways, respectively. CDKN2A mutations are found in approximately 40 of individuals with familial melanoma. 