Since the EPIYA-C segment number has also been shown to be associated with gastric cancer risk15, 16, 17, 18, 19, 20, we sought to quantitatively determine the relationship between number of EPIYA-C segments and SHP2 binding activity of CagA by reconstituting the CagA-SHP2 interaction in vitro. This evidence concerns the gene PTPN11 and gastric cancer.