GCK and type 1 diabetes mellitus: As a proof-of-concept for their possible use in drug screening, a subset of T1D and ND SC-β cell lines were treated with three anti-diabetic compounds that affect insulin secretion by different mechanisms: Sulfonylurea (tolbutamide), GLP-1R agonist (Liraglutide) and GCK activator (LY2608204) (Fig. 1g).