ERBB2 and cancer: There are several types of cancer in which the HSP90 protein is excessively activated, and as this is a protein responsible for regulating, stabilizing, and activating many other proteins, some of which are even considered oncogenic, like epidermal growth factor receptor (EGFR) or human epidermal growth factor receptor 2 (HER2), any deregulation in the signaling pathways of the cells can lead to cancer progression [72].