CD274 and neoplasm: The high immunogenicity of the NP-epitope and the ensuing generation of highly active NP-specific CTLs as observed above in BALB/c mice does not seem to be compatible with the rapid abrogation of the immune checkpoint blockade in anti-PD1/PD-L1 treated NP8 tumor mice unless one assumes that the strong immunogenicity of the NP-epitope concomitantly also leads to fast CTL exhaustion.