SMPD1 and Other metabolic disease: Acid sphingomyelinase (ASMase) can convert SM to ceramides (70), and the expression and activity of this enzyme were found to be elevated in the adipose tissue of adult and pediatric obese patients (71, 72), as well as in the serum of patients with T2D (72), suggesting that elevated ASMase activity may contribute to increased ceramide levels in individuals with metabolic disorders.