SNAI1 and metastatic malignant neoplasm: Snail is a zinc-finger transcription factor expressed in migratory processes during embryonic development(38,39) and has been implicated in the development of metastatic cancer through downregulation of VDR and the conversion of an epithelial to a mesodermal phenotype.(40) Homozygous Snail gene knockout (Snail–/–) in mice is lethal early in embryogenesis,(41) whereas heterozygous (Snail+/–) mice appear normal.