Indeed, based on pharmacokinetic/dynamic studies [29]–[31] the most adapted and indicated dose in the advanced hormone receptor-positive, HER2-negative breast cancer, advanced neuroendocrine tumors of pancreatic origin, advanced renal cell carcinoma, renal angiomyolipoma with tuberous sclerosis complex (TSC) is 10 mg/daily, but in case of toxicity, the suggested dose is 5 mg/daily. This evidence concerns the gene ERBB2 and tuberous sclerosis.