In vivo, the importance of B7H3-dependent recruitment of MDSCs is revealed by evidence of diminished pulmonary fibrosis and myofibroblast differentiation in myeloid cell-specific TERT-deficient mice, which exhibited deficient lung MDSC expansion and recruitment in response to BLM-induced lung injury, along with a reduced level of plasma sB7H3. Here, CD276 is linked to pulmonary fibrosis.