GSTM1 and cancer: For GSTM1, plenty of meta-analyses have shown that GSTM1-null could increase cancer risks in some specific organs among smokers or drinkers[104–108]; while some scholars suggested that this cancer susceptibility might not be augmented by smoking or drinking.[109,110] The outcome of this study indicated that GSTM1-null, both alone and in combination with smoking or drinking, was associated with the overall increased cancer risks.