The function of GPR156 (G protein-coupled receptor 156, Ensembl gene identifier ENSG00000175697) is as follows. Orphan G protein-coupled receptor involved in the regulation of hair cell orientation in mechanosensory organs of the inner ear. It is required to trigger a 180 degree reversal in hair cell orientation, creating a virtual line of polarity reversal (LPR) across which stereociliary bundles are arranged in opposite orientations. .