MTOR and breast cancer: Everolimus, an inhibitor of the mammalian target of rapamycin (mTOR) (Schuler et al., 1997; Dennis et al., 1999; Nashan, 2002), is used not only for treating inoperable or recurrent breast cancer but also for suppressing rejection in organ transplantation and for the treatment of tuberous sclerosis complex (Eisen et al., 2003; Tedesco Silva et al., 2010; French et al., 2016; Jeng et al., 2018).