ERBB2 and breast cancer: Furthermore, a significant BLM mRNA overexpression along with high BLM cytoplasmic localization was observed in the aggressive molecular phenotypes (including PAM50, which is a 50-gene signature that classifies breast cancer into five molecular intrinsic subtypes: Luminal A, Luminal B, HER2-enriched, Basal-like, and Normal-like) and has been associated with poor breast cancer-specific survival, possibly highlighting BLM transcript level detection as a promising biomarker (Arora et al., 2015).