MMP3 and lung cancer: In contrast, no association was found between the -735 C/T and -1171 5A/6A polymorphisms in the MMP2 and MMP3 promoter genes and lung cancer risk (adjusted OR = 0.86; 95% CI: 0.35-2.13; P = 0.749 and adjusted OR = 1.19; 95% CI: 0.84-1.67; P = 0.331, respectively).