PTPRC and neoplasm: For example, using single-cell copy number alterations, Chemi et al. have shown that cells with a CTC phenotype (EpCAM-positive, CK-positive, CD45-negative) can be genomically normal [39], while Reduzzi and colleagues have shown that dual-positive cells (CK-positive, CD45-positive) may represent hybrid fusions of tumor and stromal cells[38].