In a different case–control investigation, Wang and colleagues sought to determine whether genetic variations in the CDKAL1 (cyclin-dependent kinase 5 regulatory subunit-associated protein1-like 1) gene, linked to proinsulin conversion and insulin resistance, in conjunction with low maternal serum levels of critical metabolic and nutritional factors (specifically, L-carnitine, choline, and betaine), could function as predictive markers for GDM [58]. Here, INS is linked to gestational diabetes.