PTGER4 and colonic neoplasm: In this context, PGE2 was shown to induce EGFR transactivation and subsequent PI3K signaling via EP4, β-arrestin and c-Src in colon cancer cells [202] In addition, PGE2 via EP2 and EP4 has also shown to modify the activity of other growth factor receptors, such as insulin-like growth factor 1 receptor (IGFR) [207].