Orafacial clefts are the most frequent craneofacial malformations but the least understood; hereditary and environmental agents have been associated. Epithelia and mesenchymal interactions are important developmental mechanisms associated with normal palatogenesis as well as other extrinsic factors. Two groups of genes have been implicated in these interactions: transcription factors (homeobox) and signalling associated genes. Among the last ones, transformant growth factor beta-3 (TGFβ3) and bone morphogenetic proteins (BMPs) have been emphasysed because their relation with epithelia adhesion and epithelio-mesenchyma transformation and BMP- 4 on mesenchymal proliferation.