Molecular Basis of Triple Negative Breast Cancer and Implications for Therapy

Table 2

Six subtypes of triple negative breast cancer based on gene expression profiling.

Subtype	Gene expression profile
Basal-like 1 (BL-1)	High in the expression of genes involved in cell cycle progression, cell division, and DNA damage response pathways.
Basal-like 2 (BL-2)	High in the expression of genes involved in cell cycle progression, cell division, and growth factor signaling.
Immunomodulatory (IM)	High in the expression of genes involved in immune processes and cell signaling.
Mesenchymal (M)	High in the expression of genes involved in motility and extracellular matrix.
Mesenchymal stem-like (MSL)	High in the expression of genes involved in motility, extracellular matrix, and growth factor signaling; consistent with claudin-low Intrinsic subtype.
Luminal androgen receptor (LAR)	High in the expression of genes involved in hormonally regulated pathways.