Figure 2: The EGFR-phospholipase (PLC)-γ-PKC and EGFR-ERK/MAPK signaling pathways are involved in EGF-mediated protection of tight junctions. ERK/MAPK pathways were mainly involved in regulating barrier function by improving the gene expression of tight junction proteins such as ZO-1, claudin-1, and occludin, while PLC-γ-PKC pathways were mainly involved in regulating actin cytoskeletal architecture such as F-actin and G-actin.