ARG1 and renal fibrosis: Second, while we observed a correlation between Ccl6+Ccr2+Arg1+macrophages and the severity of renal fibrosis, and confirmed that Ccl6 promotes the migration and M2 polarization of BMDMs, we did not investigate the specific downstream signaling pathways activated by the Ccl6-Ccr2 interaction that promote fibrosis progression.