SLUG(SNAI2) is a widely expressed transcriptional repressor and member of the Snail family of zinc finger transcription factors. SLUG is expressed in placenta and in adult heart, liver, and skeletal muscle. SLUG is implicated in the generation and migration of neural crest cells in human embryos and also contributes to limb bud development. In addition, SLUG also constitutes a cellular anti-apoptotic transcription factor that effectively prevents apoptosis in murine pro-B cells deprived of IL-3. Deletion mutations in the corresponding SLUG gene are associated with the pigmentation disorders Waardenburg Syndrome and Piebaldism, while a genetic duplication resulting in SLUG overexpression is associated with a collection of congenital heart defects termed tetralogy of Fallot.