INS and type 1 diabetes mellitus: In patients presenting T1DM-like manifestations, the (A) absence of islet autoantibodies (especially, if checked at diagnosis) and (B) preserved beta-cell function (with low insulin requirements and detectable C-peptide in blood or urine) over an extended partial remission phase (at least 5 years after diagnosis) should prompt a genetic testing to rule out MODY.