Using Thy-1 YFP reporter mice, which were originally described as a tool to track neurons (22) and have been shown to mark inducible Thy-1 in cancer and wound healing (37), we found an aberrant expression of Thy-1 in skin injected with bleomycin in a manner that recapitulated the peak of fibrosis seen with histologic and gene expression parameters. The gene discussed is THY1; the disease is cancer.