PDCD1 and neoplasm: Indeed, recent findings by Rouas-Freiss et al. (75) revealed that intra- and inter-tumor heterogeneity of PD-1/PDL-1 and HLA-G/ILT2/ILT4 expression does exist in various areas of the same lesion or among different renal-cell carcinoma lesions and in tumor infiltrating immune cells.