GRK2 and obesity due to melanocortin 4 receptor deficiency: In a study published recently in Cell, Motso et al.1 developed a series of G protein-coupled receptor kinase 2 (GRK2)-biased agonists for the β2-adrenergic receptor (β2AR) which showed efficacy in stimulating muscular glucose uptake without eliciting cardiac side effects typically associated with systemically applied β-agonists.2 The candidate drug, compound 15, was well-tolerated in a phase 1 clinical trial and could provide a promising alternative treatment option for type 2 diabetes and obesity.1