The study introduces a novel cell population called "fibrocytes," which are circulating blood-borne cells with fibroblast-like properties. These fibrocytes are characterized by their positive staining for collagen I, vimentin, and CD34, and they rapidly enter sites of tissue injury, contributing to scar formation and tissue repair. The researchers isolated and characterized these cells from human and mouse peripheral blood leukocytes, finding that they exhibit a distinct phenotype and rapid proliferation. Fibrocytes were observed in both subcutaneous wound chambers and connective tissue scars, suggesting their role in both normal and pathological wound healing processes. The study also explored the potential origin of fibrocytes, concluding that they may arise from radioresistant bone marrow stromal elements or other mesenchymal cell progenitors. The findings highlight the importance of fibrocytes in tissue repair and their potential involvement in various pathological conditions characterized by excessive fibrosis.The study introduces a novel cell population called "fibrocytes," which are circulating blood-borne cells with fibroblast-like properties. These fibrocytes are characterized by their positive staining for collagen I, vimentin, and CD34, and they rapidly enter sites of tissue injury, contributing to scar formation and tissue repair. The researchers isolated and characterized these cells from human and mouse peripheral blood leukocytes, finding that they exhibit a distinct phenotype and rapid proliferation. Fibrocytes were observed in both subcutaneous wound chambers and connective tissue scars, suggesting their role in both normal and pathological wound healing processes. The study also explored the potential origin of fibrocytes, concluding that they may arise from radioresistant bone marrow stromal elements or other mesenchymal cell progenitors. The findings highlight the importance of fibrocytes in tissue repair and their potential involvement in various pathological conditions characterized by excessive fibrosis.