This was disputed recently by the study of Buchtler et al., who examined the degree of renal fibrosis in mice in which Col1a1-expressing CD45+ cells have been conditionally knocked out: when these mice were subjected to UUO or Adriamycin-induced nephropathy, their renal fibrosis was significantly reduced compared with WT mice (38). This evidence concerns the gene COL1A1 and renal fibrosis.