Among these, the SPH retrospective cohort, which was split into training (N=284) and validation (N=116) cohorts randomly by 71%–29%, and the retrospective MCC cohort with PD-L1 status (N=85) were used for training, validating, and testing the DLS to measure PD-L1 expression status non-invasively; one ICI-treated retrospective cohort (N=128) and one ICI-treated prospective cohort (N=49) were used to validate the prognostic value of the DLS and investigate the association of the DLS and clinical characteristics on the clinical outcomes. This evidence concerns the gene CD274 and Merkel cell skin cancer.