Our results are consolidated with several studies reported the association of TNF-α -308 G/A polymorphism with increased susceptibility to various cancers, including hepatocellular carcinoma, prostate cancer, oral cancer, lung cancer, cervical cancer, oesophageal cancer, breast cancer and colorectal cancer (Babapour et al., 2019; Banday et al., 2016; Pan et al., 2012; Wu et al., 2018). This evidence concerns the gene TNF and colorectal cancer.