In kidney transplantation, dosage adjustment of mTOR inhibitors sirolimus and everolimus using therapeutic drug monitoring (TDM) is recommended to prevent toxicity of adverse reactions of mTOR inhibitors such as thrombocytopenia, leucopenia, hypercholesterolemia, stomatitis, diarrhea, interstitial pneumonitis, and rejection [12]. The gene discussed is MTOR; the disease is familial hypercholesterolemia.