Allred scores for both epithelial PD-L1 (ePD-L1) and stromal PD-L1 (sPD-L1) expression were highest in invasive squamous cell carcinoma (inSCC), with mean ePD-L1 of 1.2 (SD 1.8) and sPD-L1 of 3.0 (SD 1.84), compared with progressively lower expression in in situ SCC (isSCC; ePD-L1 0.44, SD 1.24; sPD-L1 1.69, SD 1.3), actinic keratosis (AK; ePD-L1 0.1, SD 0.52; sPD-L1 1.12, SD 1.43), and normal skin (NS; ePD-L1 0; sPD-L1 0.36, SD 0.94). This evidence concerns the gene CD274 and actinic keratosis.