We identified 12 SNPs across 10 ECMrelated genes significantly associated with MDD, including ADAM metallopeptidase domain 17 (ADAM17, rs55820761), brevican (BCAN, rs11264511), CD44 molecule (CD44, rs12270356), collagen type XVII alpha 1 chain (COL17A1; rs2282436 and rs10883962), collagen type III alpha 1 chain (COL3A1; rs16830979 and rs10883962), collagen type VI alpha 6 chain (COL6A6, rs16830219), cathepsin L (CTSL, rs2274611), Kallikrein-related peptidase 2 (KLK2, rs2664156), matrix metallopeptidase 11 (MMP11, rs738791), and nicastrin (NCSTN, rs3753391). The gene discussed is KLK2; the disease is major depressive disorder.