PRL and type 2 diabetes mellitus: If our theory is proven valid via genetic studies determining the gene variants in the dopamine–PRL pathway predisposing to SCZ and consequently to T2D, screening for disease biomarkers, such as PRL levels, or for gene risk-variant carriers could be performed in children and teenagers with increased SCZ-familial risk or presenting with cognitive, developmental, emotional and/or behavioral issues, resembling possible predisposition to SCZ.