To clarify the mechanism, enormous evidence has also shown that the proliferation induced by a loss of Par3 in tumor cells is related to the abnormal expression of some important genes and the abnormal regulation of some signaling pathways, including an upregulation of P-cadherin (88) and MMP9 (77), downregulation of SNAIL1 (104), an activation of Stat3 (77) and the Tiam1/Rac1 signaling pathway (76), and a decrease in the Notch signaling pathway (85). The gene discussed is RAC1; the disease is neoplasm.