AR and Familial prostate cancer: They demonstrate that exosomal mRNA levels of these enzymes in the patients change considerably during treatment, proposing that chip‐based analysis of exosomal mRNA could predict drug resistance in GBM.[232] Del Re et al. present a new method to detect androgen receptor splice variant 7 (AR‐V7) mRNA in EVs from the plasma of patients with castration‐resistant prostate cancer.