G protein-coupled receptors (GPRs), also known as seven transmembrane receptors, heptahelical receptors or 7TM receptors, comprise a superfamily of proteins that play a role in many different stimulus-response pathways. G protein coupled receptors translate extracellular signals into intracellular signals (G protein activation) and they respond to a variety of signaling molecules, such as hormones and neurotransmitters. GPR126 (G protein-coupled receptor 126), also known as APG1, DREG, VIGR or PS1TP2, is a 1,221 amino acid multi-pass membrane protein that contains one pentaxin domain, one GPS domain and one CUB domain. Existing as three alternatively spliced isoforms, GPR126 functions as an orphan G protein-coupled receptor that, when subject to genetic variation, may influence stature and adult height.