The transcription of a gene is controlled by a transcription factor binding either glucose or lactose. When there is 0.2 mM of either glucose or lactose in the cell, the gene is transcribed at about 10% of the maximum. When there is more than 2 mM glucose in the cell, the gene is fully induced. However, when there is 2 mM lactose in the cell, the amount of transcription is approximately half of the maximum. At 40 mM of either glucose or lactose in the cell, the gene is fully induced. The transcriptional regulation is likely: