ERBB2 and breast cancer: The HER2+ EVs in the circulation of breast cancer patients may be used to predict trastuzumab therapy efficacy.[211] Krishnan et al. suggest that circulating large EVs (specifically MPs) are useful for monitoring disease progression and MDR in myeloma, and the higher levels of P‐gp+ and phosphatidylserine (PS)+ MPs are correlated with disease progression and therapy failure.