PTPRC and metastatic neoplasm: Recently, EpCAM+ CD45+ tumor cells have also been identified in non-small cell lung cancer (NSCLC) and serous epithelial ovarian cancer (SEOC) patients, and they were closely linked to an aggressive phenotype.11,12 The presence of both classical (CD45-null) CTCs and CD45-expressing macrophage-CTC hybrid cells highlights the heterogeneous tumor cells in circulation capable of seeding metastatic tumors.8,13