A 2021 Turkish clinical study that used a cross-sectional study design found significantly lower serum leptin in MS patients (6.12 ± 5.34 ng/mL) than in controls (13.02 ± 8.25 ng/mL), even after excluding individuals with diabetes, dyslipidemia, or liver dysfunction [211]. The gene discussed is LEP; the disease is myeloid sarcoma.