NR2F1 and breast cancer: Hypoxia induces glucose transporter-1 (GLUT1) and hypoxia-inducible factor 1-α (HIF1α), key dormancy genes nuclear receptor subfamily 2 group F member 1 (NR2F1), which is an orphan nuclear retinoid receptor, DEC2, a basic helix-loop-helix transcription repressor involved in circadian rhythm, cyclin dependent kinase (CDK) inhibitor p27Kip1 and chemoresistance in ER+ breast cancer cells [17].