Dear Onelamb: In one of your corrections to the article on apoptosis you included the following comment: "Much research 'quoted' without reference...)". ¿Could you please elaborate a bit more on on this (what you would like to see as "reference"), so as to make the article better? Please include these comments in the discussion section of the Apoptosis article [[1]]. Thanks in advance. --Jaimeglz pd. Sonic hedgehog (see the Wikipedia article) is part of the Hedgehog family of signaling molecules.