Fig. 2From: Assessment of peripheral biomarkers potentially involved in episodic and chronic migraine: a case-control study with a focus on NGF, BDNF, VEGF, and PGE2Correlation between headache frequency and Serum levels of NGF, BDNF, VEGF and PGE2. A NGF (B) BDNF (C) VEGF (D) PGE2; NGF: nerve growth factor; BDNF: brain-derived neurotrophic factor (BDNF); VEGF: vascular endothelial growth factor; PGE2: prostaglandin E2Back to article page