Previous work demonstrated strong upregulation of CD40 in glomerular cells 2 weeks after DOX nephropathy induction followed by loss of glomerular expression and increased expression in proximal tubular epithelium (PTEC) and cortical interstitium.20,27 Histological studies have demonstrated a rich network of fibroblasts and dendritic cells within the renal interstitium29,30,31 that would be predicted to be highly responsive to CD40 activation. This evidence concerns the gene CD40 and Nephropathy.