Flow cytometry analysis of blood samples from 10 keloid patients and 12 normal scar patients revealed that the number of circulating fibrocytes (CD45+, Col I+) in keloid patients (17.4 × 105 cells/mL) and the absolute number of CXCR4+ fibrocytes were significantly higher than those in normal scar patients [97]. The gene discussed is PTPRC; the disease is keloid.