In this study, the proportion of different immune cell populations was associated with distinct distant metastasis-free survival and, interestingly, PD-L2 emerged as a promising prognostic biomarker (contrarily to PD-L1, like in BlCa and RCC) and predictive factor (of response to radiotherapy), which may also mean it can be a promising therapeutic target [121]. Here, CD274 is linked to bladder transitional cell carcinoma.