These findings were corroborated by additional studies showing that PD-L1 expression in both tumor cells and immune cells was more pronounced in patients with BCG-unresponsive carcinomas in situ (CIS) compared to BCG-responders, suggesting that baseline PD-L1 expression could serve as a predictive marker for CIS that would not respond to BCG therapy [62,63]. The gene discussed is CD274; the disease is in situ carcinoma.