CTLA4 and neoplasm: Lin et al.’s study on MUC1 mRNA nanoparticle vaccines for TNBC treatment demonstrated their ability to activate CTLs against MUC1-expressing tumor cells and, when used alongside CTLA-4 antibodies, reduce Tregs, thereby enhancing CTL cytotoxicity and effectively modulating the tumor microenvironment to strengthen the immune response (98).