FAS and infection: One study that examined the response of H. pylori eradication in gastric MALT lymphoma showed that the decrease in the serum sFas level would be a useful marker of successful treatment.12 The other study showed that H. pylori caused a selective up-regulation of Fas mRNA and the protein expression in gastric cancer cells.13 The mean serum sFas level in male case subjects with H. pylori infection did not differ from those in subjects without the infection (2.26 pg/mL vs. 2.23 pg/mL, P = 0.90).