ESR1 and neoplasm: In addition, BIRC5-high displayed strong relationships with aggressive tumor characteristics, with higher frequency among hormone receptor (HR)-negative tumors (BIRC5-high RFD for ER-negative: 27.3%, PR-negative: 21.1%) and aggressive PAM50 subtypes (BIRC5-high RFD for LumB: 33.0%, HER2-Enriched: 28.4%, and Basal-like 49.8%).