GSTM1 and gastric cancer: Among them, however, some demonstrated a strongly increased risk for gastric cancer among those carrying the unfavourable variant of IL- who are contemporarily Helicobacter pylori positive [23], those contemporarily carrying GSTM1 null and CYP2E1 PstI/RsaI homozygous variant [26], and those contemporarily GSTM1 null and GSTT1 null [27,28].