Our results also showed that depletion of either Egr-1 or CBP can downregulate RTA transcription (upto ∼ 30% in Egr-1 depleted cells and ∼ 20% in CBP depleted cells); whereas depletion of both Egr-1 and CBP can reduce the RTA transcript levels upto ∼ 55% in both BC-3 and BCBL-1 cells after induction. This evidence concerns the gene CREBBP and breast cancer.