After analyzing genetic variants in lung cancer patients, Liu et al. proposed that the combination of RP-related SNPs, including PAI-1, TGFβ1, ITGB6, PI3CA, AKT2, and MMP1 could achieve a more accurate prediction of grade ≥ 3 RP, although extensive trials are needed to confirm this model [164]. This evidence concerns the gene MMP1 and lung cancer.