EGFR and gastric cancer: In contrast, NO has also been shown to inhibit the phosphorylation of the EGFR by the EGF, causing a downstream reduction in ERK phosphorylation in gastric cancer cells through the activation of type II cGMP-dependent protein kinase (PKG II), demonstrating both pro- and anti-stimulatory effects on the EGFR (YAO et al., 2015).