PTPRC and cancer: Other CTC isolation techniques (e.g., microfilters based on size [70]) allow additional phenotypic analysis and identification of other potentially relevant circulating cancer-associated cells, including cells that have undergone epithelial–mesenchymal transition (EMT) and down-regulated EpCAM, or which express myeloid/macrophage-markers CD45/14+ [4,5,8,27,28,71,72].