Therefore, combinations of different HSP90 inhibitors (e.g., tanespimycin, AUY922, ganetespib, and alvespimycin) with anti-HER2-based drugs have been tested in clinical trials with HER2 BC patients (in different disease stages, including tumors refractory to anti-HER2 drugs) [159,160,161,162]. This evidence concerns the gene ERBB2 and breast cancer.