S100A8 and gastric cancer: Therefore, to begin to study how CagA C-terminal polymorphism alters a host cell signaling pathway associated with gastric cancer development, we infected AGS cells with the isogenic strains and utilized Western blot to temporally monitor total CagA, CagA delivery and phosphorylation, and ERK1/2 activation in a temporal manner (see Supplementary Figure S5 for a representative Western blot compilation).