Pan Melanoma Antibody + Ki-67 serves as a tool to identify the proliferation rate of melanocytic lesions in cases in which melanocytes are sparse; there are dense lymphocytic infiltrates; and melanocytes are admixed with fibroblasts. In general, a higher proliferative fraction is seen in melanoma than in melanocytic nevi. There are many types of nevi, and some simulate melanoma closely. If the Multiplex stain shows a very low Ki-67 (DAB) labeling rate in MART-1/Tyrosinase positive cells (Fast Red), this favors benignity. A high rate, especially toward the deep part of a melanocytic lesion raises the possibility of malignancy.