This discordance may be attributed to the different molecular targets of pembrolizumab vs durvalumab (PD-1 on cytotoxic T-cells vs PD-L1 on tumor cells, respectively) or differences in study populations,59 although it is unlikely that the different maximum cycles of ICI permitted in the KEYNOTE-A18 and CALLA trials (20 and 24, respectively) would produce the contrasting results, especially because the median ICI durations in each study were similar. This evidence concerns the gene CD274 and neoplasm.