ACTA1 and focal segmental glomerulosclerosis: We found that adoptive transfer of MDSCs to doxorubicin‐induced FSGS mice for 8 weeks led to an increase in serum creatinine and proteinuria and aggravation of renal interstitial fibrosis, manifested by increased collagen deposition in Masson staining results, increased expression of α‐SMA protein in immunofluorescence and western blotting results, and increased expression of α‐SMA and collagen I mRNAs in qRT–PCR results.