CCND1 and melanoma: This systematic review and meta-analysis of 41 studies and 3451 patients, shows CCND1/cyclin D1 upregulation as a common oncogenic alteration in cutaneous, mucous, and uveal melanomas, and we carry out a comparative study of the alterations of this oncogene and its product in these different types of melanomas under the hypothesis that perhaps the upregulation of CCND1/cyclin D1 may be different in these types of melanomas and to some extent justify their different clinical behavior and prognosis.