In a language like C, the actual function is known.

The function of the protein is not known, he said.

The specific function of this gene is not yet known.

The history and function of the ship are not precisely known.

The function of these is not known, but they may be used during courtship.

The location and function of the other two proteins are not yet known.

A future permanent function of the building is not known publicly.

Their function is not known yet, although they may help in attracting prey.

The cellular function of these plant proteins is not known.

The justices of the peace therefore took on various administrative functions known as "county business".