NR2F1 and breast cancer: Moreover, methyl substitution on the indole ring (1,1- and 2,2-dimethyl DIM-C-Pyr-4) and the DIM-C-Pyr-4 N-oxide derivative was also inactive and methyl substitution (5,5′-dimethyl) on the phenyl moiety of the indole ring resulted in decreased activation of GAL4-COUP-TFI in breast cancer cell lines.