When we compared the IHC subtypes between primary BC (n = 20) and BCBM (n = 41), a similar pattern was seen in the two cohorts (P = 0.934): triple negative BC (TNBC) and HER2+ irrespective of hormone receptor status was the most common subtypes in both cohorts (Fig. 1A). This evidence concerns the gene NR4A1 and breast cancer.