Orphan nuclear receptors ERRα, ERRβ and ERRγ that belong to NR3B or type IV nuclear receptor family are well studied for their role in breast cancer pathophysiology.
The expression of orphan nuclear receptor Liver Receptor Homolog-1 (LRH-1) is elevated in breast cancer and promotes proliferation, migration and invasion in vitro.
Breast cancer has been redefined into three clinically relevant subclasses: (i) estrogen/progesterone receptor positive (ER+/PR+), (ii) HER2/ERRB2 positive, and (iii) those lacking expression of all three markers (triple negative or basal-like).
For estrogen receptor (ER)-positive patients who received adjuvant tamoxifen, amplification of HSD17B1 was related to decreased breast cancer survival (P=0.017), whereas amplification of ERRB2 was not.