PTPRC and neoplasm: Cellular profiling of samples from three representative patients (Fig. 1) demonstrates the extensive heterogeneity of CTC markers: where a large frequency of exclusion channel negative cells (CD11b−, CD14−, CD34−, CD45−, CD235a−) did not simultaneously express all tumor‐specific markers (CK, EpCAM, CAIX, and CAXII).