As far as the efficacy of MHC class II-dependent killing, of note, although the repertoire of naturally occurring cytotoxic CD4+ T cells in bladder cancer is noted to be restricted compared with other CD4+ T cell subsets (Oh et al., 2020), even within multimer-selected cytotoxic CD4+ T cell lines, the repertoire is polyclonal (Cachot et al., 2021), and it is likely that only a select number of TCR clonotypes are of sufficient avidity to trigger killing. This evidence concerns the gene CD4 and urinary bladder cancer.