A representative example is that a study on colon cancer cell lines and BALB/C nude mouse model shows that, miR-21-5p and miR-155-5p are transferred to colorectal cancer cells through MDE and combined with BRG1 coding sequence to regulate the expression of BRG1, so as to mediate the migration and invasion of colorectal cancer cells and inhibit antitumor immune response [85]. The gene discussed is SMARCA4; the disease is malignant colon neoplasm.