MTOR and cancer: Mechanistically, honokiol downregulates AKT phosphorylation and upregulates PTEN expression, resulting in suppression of the PI3K/AKT/mammalian target of rapamycin (mTOR) pathway, an essential driver of cancer cell survival and proliferation.24 These findings support the potential of combining honokiol with lapatinib as a novel strategy for HER2-positive breast cancer.