CD5 and pulmonary fibrosis: Finally, the elevated levels of CD5+CD4+ and CD5+CD8+ may be explained by their possible role in the pathogenesis of lung fibrosis, which is also supported by the presence of macrophages in the BALf and lung parenchyma of ischemic animals 3, 7, and 90 days after reperfusion, since they are also thought to be important mediators in the regulation of fibroblast function [37,38,57,58].