CD44 and gastric cancer: In GC patients, norepinephrine (NE) induces gastric EMT and enhances the invasive and migratory capabilities of GC cells through the activation of multiple pathways, including β2-AR-HIF-1α-Snail signaling, β2-AR-STAT3-CD44 signaling, and β2-AR-MMP7 signaling [96–98].