Slug, a member of the Snail family of C2H2-type zinc finger transcription factors, was initially identified to be involved in epithelial-mesenchymal transitions as well as the formation of the neural tube during vertebrate embryogenesis. Like Snail, Slug transcription can be induced by growth factors such as FGF, BMP, and TGF-beta. Once expressed, Slug will bind E-box regions of promoters and repress transcription of genes such as E-cadherin and Claudin-1. More recently, its expression in breast, esophogeal, and colorectal carcinomas has been correlated with poor prognosis for survival. Furthermore, Slug can protect hemapoietic progenitor cells from radiation-induced apoptosis by repressing the p53-mediated transcription of Puma, a BH3-only antagonist of the anti-apoptotic members of the Bcl-2 family. Slug antibody has no cross-reactivity to Snail protein.