- Melanoma antigen recognized by T-cells (MART-1) and gp100 are two genes found in melanoma cells. An experimental procedure developed for treating patients with advanced melanoma uses these genes and a type of virus to make special cells called anti-MART-1 and anti-gp100 cells, which are designed to destroy the patient's tumor. The cells are created in the laboratory using the patient's own tumor cells or blood cells.