APOL1 and type 1 diabetes mellitus: Of the 28 serum proteins studied, five of them—alpha-2-macroglobulin (A2M), apolipoprotein A-IV, apolipoprotein L1, insulin-like growth factor 2, and phospholipid transfer protein—were significantly associated with T1DM status, with A2M being 1.6-fold higher in T1DM.