MTOR and breast cancer: In the EFM119 breast cancer cells, the resistance to palbociclib is linked to activation of the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway [50], whereas, in ovarian cancer cell lines such as ID8 and HOC7, the impact of the MAPK pathway was additionally evidenced [51].