CD8A and neoplasm: The correlation between the immune infiltration of CD8+ T-cells and SPDL1 expression in tumor tissues (BRCA, HNSC-HPV+, LIHC, LUSC, PAAD, PRAD, SKCM, THYM, UCEC and UVM) was found to be statistically significant based on four algorithms (Additional file 2: Fig. S10).