PDCD4 and colonic neoplasm: In addition, focal adhesion kinase (FAK) initiated by integrin β4 was found to be expressed in the nuclei of colon cancer cells, indicating that the activation of integrin β4 downstream molecules is also associated with abnormal cell proliferation [30], and other pathways such as miRNA-21-integrin β4-PDCD4 can affect cell viability [31].