To validate the difference in immune cell infiltrates between UC and SqD regions noted by immune cell deconvolution analysis of the RNAseq data, we performed immunohistochemical staining for PD-L1 and observed significantly higher PD-L1 protein expression on tumor cells in the SqD as compared to UC regions of 14 of 15 tumors (Fig. 4e and Supplementary Table 1, p = 0.02, paired Wilcoxon rank sum test). The gene discussed is CD274; the disease is neoplasm.