Two gelatinase B/MMP-9 coding region single nucleotide polymorphisms rs2250889 (P574R) and rs17576 (R279Q) have been associated with risk of lung cancer and lung cancer metastasis [32], and with reduced overall survival of patients with loco regionally advanced nasopharyngeal carcinoma, characterised by increased tissue gelatinase B/MMP-9 expression [33,34], lymph node metastasis in gastric cancer [35] and risk of gallbladder cancer [36] but these SNPs do not appear to associate with colon cancer susceptibility in a Chinese cohort study [37]. Here, MMP9 is linked to lung cancer.