Dopamine receptors, encoded by several genes (eg, DRD1, DRD2, DRD3, DRD4, and DRD5), mediate the effects of dopamine in the nervous system.31 Variations in dopamine receptor genes, particularly DRD2 and DRD4, have been investigated for their association with fibromyalgia.14 These polymorphisms may affect receptor function and dopamine signaling pathways, influencing pain processing and stress reactivity. Here, DRD4 is linked to fibromyalgia.