The thick and hyalinised collagen bundles that characterise Intermediate DR are also observed in keloids, in which fibroblasts overexpress various growth factors, including transforming growth factor β (TGF-β).42 In the tumour microenvironment surrounding these bundles, TGF-β, a well-established inducer of EMT,43,44 is highly likely to be upregulated. The gene discussed is TGFB1; the disease is neoplasm.