MAPK3 and colonic neoplasm: Therefore, ERK1/2 signaling stimulated by Ucns in cardiomyocytes is mediated through CRF2R, which appears to be the main mediator of the cardiac stress response (78, 79), rather than through CRF1R. Additionally, recent observations also indicate that CRF2R controls the cellular organization and colon cancer progression, specifically through the Src/ERK pathway (80, 81).