1,1-Bis(3′-indolyl)-1-(4-pyridyl) methane (DIM-C-Pyr-4) has been identified as a unique compound among as series of heteroaromatic C-DIMs that activates a COUP-TFI-GAL4 chimera containing COUP-TFI fused to the DBD of GAL4 in MCF-7 and ZR-75 breast cancer cells transfected with a construct (GAL4-luc) containing 5-tandem GAL4 response elements linked to luciferase. Here, NR2F1 is linked to breast cancer.