SNAI1 and carcinoma: Snail family transcription factors, consisting of Snai1 (also known as Snail) Snai2, and Snai3 (also known as Slug and SMUC respectively), are a family of zinc finger transcriptional repressors that are key regulators of epithelial-mesenchymal transitions (EMTs) during embryonic development, and of metastasis in epithelial-derived carcinomas.