Although the precise function of this protein is unknown, researchers believe that it plays a critical role in the development of facial bones and related structures.

[7] The treacle protein is involved in rRNA gene transcription through its interaction with upstream binding factor (UBF).

TCOF1 mutations lead to the production of an abnormally small, nonfunctional version of treacle or prevent the cell from producing this protein.

Researchers speculate that a loss of treacle reduces the production of rRNA in parts of the embryo that develop into facial bones and tissues.

It is not known how loss of the treacle protein causes the specific problems with facial development found in Treacher Collins syndrome.