[5][6] Snail is a family of transcription factors that promote the repression of the adhesion molecule E-cadherin to regulate epithelial to mesenchymal transition (EMT) during embryonic development.

The Drosophila embryonic protein SNAI1, commonly known as Snail, is a zinc finger transcriptional repressor which downregulates the expression of ectodermal genes within the mesoderm.

[9] Prostaglandin E2 (PE2), an important hormone in homeostasis and maintaining normal fertility and pregnancy, stabilizes SNAI1 post-transcriptionally and, therefore, also plays a role in embryogenesis.

When the prostaglandin signaling pathway is compromised, SNAI1 transcriptional repressor activity decreases, increasing E-cadherin protein levels during gastrulation.

[10] Snail gene may show a role in recurrence of breast cancer by downregulating E-cadherin and inducing an epithelial to mesenchymal transition.