INS and type 2 diabetes mellitus: This has been considered by an international expert panel that recommends a personalized treatment depending on three categories of random C-peptide: if levels are less than 0.90 ng/mL (0.3 nmol/L), a multiple-insulin regimen is suggested; those with levels between 0.90 and 2.0 ng/mL (0.3–0.7 nmol/L) could be treated with insulin in combination with other therapies in a flexible scheme; and those with levels higher than 2.0 ng/mL (0.7 nmol/L) could be treated according to T2D guidelines.