A published dataset with available pre- and post-treatment PD-L1 expression in patients who received neoadjuvant atezolizumab therapy revealed a moderate but significant increase in PD-L1 expression in the post-treatment tissues, however this increase was much lower compared to that we found in the serum samples and therefore we suppose that bladder cancer cells may not be the primary source of the increased post-treatment serum PD-L1 flare-up [33]. This evidence concerns the gene CD274 and urinary bladder cancer.