CREBBP and breast cancer: Another ER transcriptional co-activator in breast cancer is CBP/p300-interacting transactivator with Glu/Asp-rich carboxy-terminal domain 2 (CITED2) which is overexpressed in breast cancer tissues and is associated with worse clinical outcome.360 Increased expression of this protein may result in estrogen-independent ER activation, thereby reducing estrogen dependence and response to hormone therapies.361 Jayaraman et al.362 has also documented that CITED2 can modulate macrophage recruitment to influence breast cancer growth.