SNAI1 and cancer: Repression of E-cadherin, frequently observed in human malignant tumors, is mediated at the transcriptional level by the δEF1 family of two-handed zinc-finger factors (δEF1/ZEB1 and SIP1/ZEB2), proteins of the Snail family (Snail, Slug, and Smuc), and basic helix-loop-helix factors (Twist and E12/E47) 4.