SMAD7 and colorectal carcinoma: In this study, we verified the following: 1) miR-4775 is more highly expressed in metastatic CRC tissues than in non-metastatic tumor tissues; 2) high miR-4775 expression predicts poor prognosis in CRC patients; 3) miR-4775 promotes CRC cell invasion, metastasis and EMT by activating Smad7-dependent TGFβ signaling; and 4) miR-4775-mediated Smad7/TGFβ activation predicts poor survival in CRC patients.