The presence of tPA mRNA was detected in human skin wounds and ulcers in the basal epidermis at the ulcer margin, and tPA protein in all layers of epithelium, while in mouse wounds, tPA immunoreactivity was observed from days 5 to 10 in keratinocytes located superficially in the epidermal outgrowths [46]. The gene discussed is PLAT; the disease is ulcer disease.