Studies manifested that ECT2 is regulated by miRNA in the development of various cancers: miR-194 inhibits cancer cell proliferation by targeting and regulating ECT2 in cholangiocarcinoma [16]; miR-490-5p inhibits metastasis of liver cancer by downregulating E2F transcription factor 2 (E2F2) and ECT2 [17]; miR-223-3p suppresses proliferation, invasion, and migration of breast cancer cells by targeting ECT2 [18]. This evidence concerns the gene E2F2 and breast cancer.