CD274 and neoplasm: The co-culturing of primary tumor epithelia with endogenous, syngeneic tumor-infiltrating lymphocytes (TILs), which comprise patient-derived organoids (PDOs), enables the successful modeling of the immune checkpoint blockade (ICB) with anti-PD-1- and/or anti-PD-L1, expanding and activating tumor antigen-specific TILs and eliciting tumor cytotoxicity [101].