RARRES2 and Headache: Genetically, CD302 was associated with headache (P = 2.60 × 10−5), RARRES2 was associated with neck or shoulder pain (P = 3.94 × 10−4), TNFRSF1B was associated with back pain (P = 7.96 × 10−5), and CD74 was associated with hip pain (P = 3.21 × 10−4).