Systems and methods for validating immune therapy that targets patient- and tumor-specific neoepitopes are presented in which cellular components are identified and/or used that present patient- and tumor-specific neoepitopes. Presence of these neoepitopes confirms the suitability of the neoepitopes. Advantageously, synthetic antibodies are created based on in silico analysis of the tumor genome and RNA or phage display, and can be used to isolate cellular components, and especially circulating tumor cells, metastatic cells, and/or exosomes and microvesicles.