Since positive or negative selection is not needed, all circulating cells are captured and analyzed via proprietary technology. 36 Short Title: Enzalutamide Vaccine in mCRPC Version Date: 03/29/2022 Multiplex analysis technologies have been developed to examine the levels and activities of androgen receptor. The evaluation of CTCs may give valuable insight into how treatment affects changes in CTC phenotype, such as AR splice variants, and how such changes are associated with clinical outcomes. 4.1.4.1 Blood collection At the time of enrollment and at restaging visits, one 10 mL Streck Cell-Free DNA (brown-black top) tube will be collected. Dr.