ARHGEF4 and colorectal neoplasm: Promotes the rapid degradation of CTNNB1 and participates in Wnt signaling as a negative regulator. APC activity is correlated with its phosphorylation state. Activates the GEF activity of SPATA13 and ARHGEF4. Plays a role in Hepatocyte growth factor (HGF)-induced cell migration. It is required for MMP9 up-regulation via the JNK signaling pathway in colorectal tumor cells. Acts as a mediator of ERBB2-dependent stabilization of microtubules at the cell cortex. It is needed for the localization of MACF1 to the cell membrane which is critical for its function in microtubule stabilization.