ERBB2 and breast cancer: For instance, DCZ3112 demonstrated efficacy in trastuzumab-resistant HER2-positive breast cancer cells, suggesting its potential to restore sensitivity in tumors unresponsive to receptor tyrosine kinase inhibitors.57 Similarly, platycodin D was shown to potentiate the effect of mTOR inhibitors by blocking feedback activation of AKT, a common resistance mechanism following mTOR pathway suppression.44 Additionally, compound 11g successfully reversed drug resistance in A549 lung cancer cells, further emphasizing the role of Hsp90–Cdc37 disruption in overcoming acquired therapeutic resistance.50