The regulator gene produces repressor protein.

It is the gene for cystic fibrosis. CFTR means Cystic Fibrosis Transport Regulator.

A regulator.

The operon segment composed of the gene that codes for a protein repressor is called the regulatory gene. This gene produces the repressor protein that can bind to the operator region of the operon, preventing transcription of the structural genes when the repressor is bound.

The CFTR gene provides instructions for making a protein called the cystic fibrosis transmembrane regulator.