PD1/PD-L1 pathway inhibitors such as pembrolizumab, nivolumab, atezolizumab have been approved from several solid tumors (melanoma, kidney, lung cancer, head and neck, Merkel cell tumors, Hodgkin’s lymphoma), and PD-L1 expression on tumoral cells (TC) or in immune-infiltrate (IC) has been associated with response to checkpoint inhibitors, in some cases [4], but PD-L1 expression predictive value remain controversial [5, 6]. Here, CD274 is linked to Merkel cell skin cancer.