The 4-pyridyl compound 4 showed stronger activation of the orphan receptor chicken ovalbumin upstream promoter-transcription factor I (COUP-TFI) in breast cancer cells than its 3-pyridyl and 2-pyridyl analogs at doses of 5, 10, and 15 μmol/L in a luciferase gene reporter assay, and 4 also induced early growth response 1 (Egr-1) activation[50]. Here, NR2F1 is linked to breast cancer.