CXCL12 and Schnyder corneal dystrophy: Once fibrocytes home and extravasate into the lung dependent on the CXCL12/CXCR4 biological axis, the data from our NY1DD mice suggests that they play a major role in functioning as mesenchymal progenitor cells for the production of extra-cellular matrix and contribution to fibrosis in the lungs of patients with SCD.