Lipson et al. analyzed 67 specimens from 49 patients for PD-L1 expression by immunohistochemistry and demonstrated tumor cells and immune infiltrates expressed PD-L1 (49 % and 55 %, respectively) with 97 % of PD-L1-expressing MCC cells geographically associated with immune infiltrates [15]. Here, CD274 is linked to Merkel cell skin cancer.