Recently, in a Polish cohort, two variants of mTOR (p.Gln2063ArgfsTer3 and p.Phe871Cys) were found in two subjects affected by MODY-X, in exclusive dietary and behavioral treatment, with positive family history for DM, normal levels of fasting C-peptide, nonelevated HbA1c at diagnosis, and absence of pancreatic islet autoimmunity. The gene discussed is MTOR; the disease is diabetes mellitus.