Since PI3Kα is frequently mutated or activated in BCs, we chose to investigate the effects of alpelisib combined with PTX in response to ICI (anti-PD-1 and anti-CTLA-4) using a luminal, TNBC-like PyMT orthotopic implantation mouse model of breast cancer in C57BL/6 mice. Here, CTLA4 is linked to breast cancer.