XRCC4 and lip and oral cavity carcinoma: Similar to our results, Tseng et al. [20] investigated the effects of XRCC4 codon 247 polymorphism on oral cancer in Taiwan (another Chinese population) and found that persons carrying XRCC4-AS had a higher cancer risk than those with XRCC4-AA (adjusted OR = 2.04, p = 0.023).