PPARG and gastric cancer: In 3 studies related to gastric cancer, Ala12 allele has been found to be associated with increased risk of gastric cancer [199–201] and this effect of PPARγ is probably related to gastric mucosa atrophy and Helipobacteria pylori infection since the presence of Ala12 allele does not increase the risk of gastric cancer in H. pylori-negative subjects [199].