The present invention provides a marker which can be used as an indicator for efficacy prediction of an mTOR related anticancer agent or prognostic prediction, and a novel anticancer agent. The present invention provides a method for efficacy evaluation of a cancer drug, and, specifically, a prediction method for the efficacy of an mTOR-related cancer drug by detecting NRF2 abnormality. In addition, the present invention provides a prognostic prediction method for cancer, and, specifically, a prediction method for the prognosis of cancer by detecting NRF2 abnormality. Furthermore, the present invention provides a novel anticancer agent that targets NRF2.