CD274 and Merkel cell skin cancer: Immunological findings that have been correlated with an improved prognosis among patients with MCC include increased CD8+ T cells (either tumour-infiltrating T cells or those located at the tumour periphery), tumour-infiltrating MCPyV-specific T cells and tumour programmed cell death 1 ligand 1 (PD-L1) expression111,145–149.