MTHFR and lung cancer: A meta-analysis revealed that the MTHFR C677T polymorphism was significantly associated with an increased risk of lung cancer in both Asian and global populations, yet this association was not observed in Caucasian populations—TT vs. CC, OR: 1.518, 95%CI = 1.220–1.890; CT vs. CC, OR: 1.053, 95%CI = 0.940–1.179 (68).