The phrase "Mothers against" was added, since mothers often form organizations opposing various issues, e.g., Mothers Against Drunk Driving, or (MADD). The nomenclature for this protein is based on a tradition of such unusual naming within the gene research community.
The phrase "Mothers against" was added to emphasize the role of mothers in forming oppositional groups, similar to the example of Mothers Against Drunk Driving (MADD). The protein's nomenclature is based on a tradition of unconventional naming used in gene research.