The GEC-ESTRO recommends performing APBI only for a low-risk group that includes women aged at least 50 years with unicentric, unifocal, pT1–2 (≤ 3 cm), pN0, nonlobular invasive breast cancer with any hormone receptor status and negative margins by at least 2 mm [13]. Here, NR4A1 is linked to invasive breast carcinoma.