4. Documented triple negative disease by immunohistochemistry (IHC) and/or in situ hybridization based on local testing (preferably assessed on the most recent tumour biopsy available). TN is defined as negative hormone receptor status (< 1% of tumour cells with ER and PgR expression) and HER2-negative status (defined as IHC score 0/1+ or negative by in situ hybridization defined according to local criteria).