According to van Nimwegen et al., elevated levels of TNF-α and IL-6 in patients with SCZ or schizoaffective disorder who were not taking antipsychotic medication may inactivate phosphatidylinositol-3-kinase—a key enzyme in the insulin receptor pathway—resulting in reduced glucose transport to target tissues via decreased GLUT-4 expression and development of insulin resistance [176]. This evidence concerns the gene IL6 and Insulin resistance.