Molecular classification of breast cancer is based on:

Molecular classification of breast cancer is based on gene expression profiling. "Gene expression profiling, which can measure the relative quantities of mRNA for essentially every gene, has identified five major patterns of gene expression in the NST group: luminal A, luminal B, normal, basal-like, HER2 positive. These molecular classes correlate with prognosis and response to therapy, and thus have taken on clinical impoance".