GSTM1 and GSTT1 null genotype increase the risk of hepatocellular carcinoma: evidence based on 46 studies. - Chen, Shu; Li, Shanli; Zheng, Yi; Yang, Pengtao; Lin, Shuai; Deng, Yujiao; Xu, Peng; Zhou, Linghui; Hao, Qian; Zhai, Zhen; Wu, Ying; Dai, Zhijun; et al. (Cancer Cell International, 2019)