Detail analyses indicated that SUMOylation could enhance the transcriptional repression activity of Slug by recruiting more corepressors (like Sin3A, CtBP, HDAC1 or HDAC2), decreasing its downstream target gene expressions (such as E-cadherin, claudin 1 and occludin) and promoting cancer cell migration, invasion, and metastasis (Fig. 7). This evidence concerns the gene SNAI2 and cancer.