PSAP and intervertebral disk degenerative disorder: Ligand binding induces endocytosis followed by an ERK phosphorylation cascade.[57, 58] As a receptor for OCN, it regulates oligodendrocyte differentiation and myelination in the central nervous system.[59] Our study adds to this body of literature by demonstrating that GPR37 is essential for PSAP‐mediated macrophage polarization and TGFβ secretion in IDD.