Thus, we assessed the relevance of the Numb isoforms, measured by reverse transcription–quantitative PCR (qPCR; RT-qPCR), to the natural history of BCs in a case cohort of 890 patients (See also the RNA purification and quantitative real-time PCR analysis and the Selection of breast cancer patients and statistical analysis sections of Materials and methods for details). Here, NUMB is linked to breast carcinoma.