CDKN2A is made up of four sections of exons – exon 1β, exon 1α, exon 2, and exon 3. These exons are used to create two proteins named p16 and p14ARF. Protein p16, created by exon 1α and exon 2, is responsible for tumor creation of genetic melanoma. When working normally, p16 binds to the cyclin dependent kinases CDK4 to inhibit their ability to create tumors, but when inactivated the suppression no longer occurs. When a mutation occurs in protein p16, it prevents the protein kinase of CDK4, which results in the inactivation of the tumor suppressor gene. Thus, kick starting the development of melanoma. Melanoma only occurs in a small proportion of the population. Only 10% of those who have melanoma acquired it genetically. This disease is an autosomal dominant gene. If only two family members have melanoma, there is a 5% chance somebody in the next generation will acquire the mutated gene. Also, there is a 20-40% chance of getting hereditary melanoma in a family if 3 or more people in the past generation had melanoma. For those who carry the hereditary mutated gene CDKN2A, acquiring skin cancer is a lot easier. Those who have the gene are far more likely to get melanoma a second or third time compared to those who don't genetically have this gene. The population that is affected by this mutation has a high familial history of melanoma or atypical moles and birth marks in large numbers, a history of primary melanoma/cancers in general, immunosuppression, skin that burns easily and doesn't tan, freckling, blue eyes, red hair, or a history of blistering. People with these high risk factors are more likely to carry inherited mutations in CDKN2A. For those who have a gene mutation, the severity is also dependent on the environmental surroundings. Out of those who carry the gene, those who express the phenotype and actually developed melanoma have a history of more sun exposure, and light skin compared to those who also had the gene but never actually developed melanoma. This suggests that this gene co-works with ones surrounding environment. If two individuals are selected who carry the CDKN2A mutation, and both genetically have the same probability of acquiring skin cancer, but one is from Australia and the other is from Europe, there is a 58% the European will acquire cancer compared to a 91% chance the Australian will get it.