CD274 and neoplasm: Notably, no correlation was found between the PD-L1 gene copy number and PD-L1 expression (r = 0.053; p = 0.607; n = 97; Figure 2A) and not between the PD-L1/cen9 ratio and PD-L1 positive tumor cells (r = 0.087; p = 0.397; n = 97; Figure 2B).