CTLA4 and cutaneous melanoma: In addition, several vital immune-checkpoint-relevant genes were also analyzed and indicated that the risk score was significantly associated with the expression of the checkpoint markers, PD-1 (PDCD1), PD-L1 (CD274), and CTLA-4 (Figure 5A), implicating the potential roles of the signature model in the response to immunotherapy in cutaneous melanoma patients.