MTOR and neoplasm: Trials that combine the CDK4/6 inhibitors with various PI3K/AKT/mTOR inhibitors (ClinicalTrials.gov Identifiers: NCT03128619, NCT03006172, NCT02684032, NCT02732119, NCT02871791, NCT02599714) are ongoing, with the aim to inhibit tumor growth and prevent relapse.