According to the findings of the GEICAM 2009-03 ConvertHER study, although the intrinsic subtype is predominantly maintained during metastatic progression, luminal/HER2-negative tumors acquire a luminal B or HER2-E profile during the metastatic process, highlighting the tumor evolution and the acquisition of oestrogen independence along the disease progress [46]. Here, ERBB2 is linked to neoplasm.