NR4A1 and breast cancer: The level I evidence thus generated led to a modification in the clinical practice guidelines allowing radiation omission after breast-conserving surgery in women ≥ 70 years with T1N0, hormone receptor-positive early breast cancers who are committed to complete a 5-year course of endocrine therapy [16] as low compliance with endocrine therapy is associated with poor locoregional control when radiation therapy is also being omitted from the treatment plan [17].