Melanoma is a type of skin cancer in which melanocytes— the cells that give skin its tan or brown color—start to grow out of control. While less common than some other types of skin cancer, melanoma is more likely to grow and spread. Cancer cells use a variety of ways to avoid the body’s natural defense—the immune system—to continue to grow, invade, and spread. In melanoma, molecular interactions between PD-1 on our immune system’s T-cells and PD-L1 on cancer cells drive whether or not the body’s immune system will attack a cancer cell. This program will look at the cellular underpinnings of melanoma, as well as agents—known as checkpoint inhibitors—that target PD-1 or PD-L1 for improved management of this condition.