MMP1 and migraine disorder: The top five identified proteins having a pleiotropic effect at the gene level with migraine are cathepsin S (CTSS, Pbinomial-test = 2 × 10–29), chromodomain Y-linked 1 (CDY1, Pbinomial-test = 2 × 10–21), follistatin (FST, Pbinomial-test = 2 × 10–21), matrix metallopeptidase 1 (MMP1, Pbinomial-test = 2 × 10–21), RB binding protein 5, histone lysine methyltransferase complex subunit (RBBP5, Pbinomial-test = 4 × 10–21).