IGFBP2 and Other metabolic disease: Furthermore, some genes encoding key enzymes associated with metabolic disorders, including Igf1 (insulin-like growth factor 1), Igfbp2 (IGF binding protein 2), Acly (ATP citrate lyase), and PC (pyruvate carboxylase), have been observed to have a specific methylation signature that distinguishes NAFLD from other liver disorders1.