PTPRC and neoplasm: High CTC levels, as enumerated with the CellSearchTM assay, which specifically detects tumour cells with epithelial phenotype, defined as 4’,6-diamidino-2-phenylindole (DAPI)+, CK+, CD45- cells, are associated with poor clinical outcome, i.e. shorter progression free survival (PFS) and overall survival (OS), in breast, colorectal, and prostate cancers (3, 9, 10, 12–18).