Mads and Smads in TGF beta signalling.

The discovery of the Mothers against dpp (Mad) gene in Drosophila has opened a window on an entirely unique signalling pathway that functions to mediate responses to the tumour growth factor beta (TGF beta) superfamily. This pathway, which is comprised of a family of proteins related to Mad, acts to convey signals directly from TGF beta receptors to the nucleus and is implicated in the pathogenesis of human diseases.