NR4A1 and breast cancer: Triple negative breast cancer (TNBC) lacks three important hormone receptors (ER, PR and HER2) and is responsible for 20% of all cases of breast cancer.3, 4, 5, 6 Of the intrinsic subtypes of breast cancer, TNBC is considered the most lethal subtype due to its clinically aggressive behavior and the absence of targeted therapies.3