As to MMP8, Shen et al[41] reported that the rs11225395, rs34009635, and rs35866072 polymorphisms are not associated with the increased risk of lung cancer in Taiwan district, however, González-Arriaga et al[42] found that the rs215502 of MMP8 acted as a protective role and decreased the lung cancer risk in Spanish. Here, MMP8 is linked to lung cancer.