Despite this, a Phase II clinical trials sponsored by Georgetown University started in 2021 with the scope of evaluating the efficacy and safety of the mTOR inhibitor SM-88 (a modified dysfunctional tyrosine) in combination with three subtherapeutic conditioning agents (PHT, methoxsalen and sirolimus, i.e., rapamycin, another mTOR inhibitor), in patients with metastatic HR+/HER2- BC [97]. This evidence concerns the gene MTOR and breast cancer.