Since the activation of EGFR can initiate several signal transduction pathways including MAPK/ERK, PI3K/Akt, JAK/STAT and PLCγ1-mediated pathways [7], [8], the blocking effect of PKG II on activation of EGFR suggests that this enzyme may have a wide-range inhibitory effect on signal transduction and the related biological activities of gastric cancer cells. Here, EGFR is linked to gastric cancer.