Mothers against decapentaplegic

Mothers against decapentaplegic homolog 2, one of the nine homologues of mothers against decapentaplegic.

Mothers against decapentaplegic is a protein from the SMAD family that was discovered in Drosophila. The SMAD proteins are homologs of both the Drosophila protein "mothers against decapentaplegic" (MAD) and the C. elegans protein SMA. The name is a combination of the two. During Drosophila research, it was found that a mutation in the gene MAD in the mother repressed the gene decapentaplegic in the embryo. The phrase "Mothers against" was added as a humorous approach since mothers often form organizations opposing various issues e.g. Mothers Against Drunk Driving (MADD).^{[citation needed]}

Several human homologues are known:

• Mothers against decapentaplegic homolog 1
• Mothers against decapentaplegic homolog 2
• Mothers against decapentaplegic homolog 3
• Mothers against decapentaplegic homolog 4
• Mothers against decapentaplegic homolog 5
• Mothers against decapentaplegic homolog 6
• Mothers against decapentaplegic homolog 7
• Mothers against decapentaplegic homolog 9