develops from develops from circulating fibrocyte monocyte-derived fibrocyte Cultured human fibrocytes are MHCI-positive, MHCII-positive, CD1a-negative, CD3-negative, CD4-negative, CD8-negative, CD10-negative, CD11b-positive, CD13-positive, CD14-negative, CD16-negative, CD18-positive, CD19-negative, CD25-negative, CD29-positive, CD32-positive, CD33-negative, CD34-positive, CD38-negative, CD40-positive, CD44-negative, CD45RO-positive, CD49a-positive, CD49b-positive, CD49c-negative, CD49d-negative, CD49e-positive, CD49f-negative, CD56-negative, CD58-positive, CD61-positive, CD64-positive, CD70-negative, CD71-positive, CD80-positive, CD83-negative, CD86-positive, CD103-negative, CD105-positive, CD181-positive, CD182-negative, CD183-positive, CD184-positive, CD185-negative, CD186-negative, CD191-positive, CD192-negative, CD193-positive, CD194-positive, CD195-positive, CD196-negative, CD197-positive, CD199-positive, desmin-negative, F4/80-positive, Gr1-positive, LSP-1-positive, MHCI-positive, MHCII-positive, alpha-SMA-negative, TCRab-negative, TCRgd-negative, and vimentin-positive. Fibrocytes are also capable of secreting angiogenin, bFGF, CCL2, CCL3, CCL4, CCL8, CXCL1, type I collagen, type III collagen, CTGF, fibronectin, GM-CSF, IL-1a, IL-6, IL-8, IL-10, M-CSF, MMP-9, PDGF-A, TGF-alpha, TGF-beta1, TNF-alpha, and VEGF-A. A bone marrow-derived cell that predominantly develops from myeloid lineage-restricted progenitor cells and circulates in peripheral blood, characterized by co-expression of hematopoietic markers CD45 and CD34 along with stromal markers including collagen type I in both humans and mice (Chesney et al., 1997; Blakaj and Bucala, 2012). This spindle-shaped cell exhibits a unique dual identity, functionally bridging immune and stromal compartments with characteristics of both monocytes and fibroblasts. Predominantly arising from circulating monocytes, it migrates to injury sites via chemokine receptors and participates in wound repair through extracellular matrix deposition, cytokine secretion, and antigen presentation via MHC class II. As mesenchymal progenitors, fibrocytes can differentiate into fibroblasts, myofibroblasts, and adipocytes, contributing to both physiological repair and pathological fibrosis (Blakaj and Bucala, 2012). FMA:63879 stromal cell myeloid lineage restricted progenitor cell progenitor cell