Nalawade et al. developed TR2.41BB, a new chimeric co-stimulatory receptor, which encoded the scFv of the TR2 agonist antibody DS- 8273a followed by a 41BB endo-domain, and they validated it in three different breast cancer models to show that its co-expression on CAR-T cells augmented the anti-tumor effectiveness of CAR-T cells targeting MUC1 or HER2 [56]. This evidence concerns the gene MUC1 and breast cancer.