HLA-C and cancer: Further analysis of the ability of CD69 and SBK1 to predict response to PD-1/PD-L1 blockade cancer immunotherapy using IPS showed that the levels of CD69 correlated positively with MHC and EC in 31 of 33 tumors, negatively with SC and CP in 32 of 33 tumors, and positively with IPS in 14 of 33 tumors (Figures 6B, 7A, Supplementary Table 5).