PDCD1 and nonpapillary renal cell carcinoma: To explain the potential biological relevance of detected interaction in relation to ccRCC development, two earlier justified assumptions were made: 1) increased expression of PD-L1 on tumor cells in individuals with C allele in rs10815225 (GC + CC) as compared to those with rs10815225 GG and 2) decreased expression of PD-1 on T cells in individuals with rs7421861 TC genotype in comparison to subjects with rs7421861 TT or CC genotype.