Donald E. Ingber soon discovered that a fungus, "Aspergillus fumigatus", secreted a chemical, fumagillin, that inhibited angiogenesis. Takeda performed medicinal chemistry to optimize it, leading to development of TNP-470. Folkman's team later tested it in adults with hemangiomas; they also used interferon alpha, an already approved drug that they had already shown to be an angiogenesis inhibitor, to treat infants with hemangiomas in some of the first clinical trials of angiogenesis inhibitors which were published in 1992. In these trials they also studied the levels of fibroblast growth factor in the urine of the trial subjects and published that work in 1994; these were some of the first explorations of the use of biomarkers in clinical trials as surrogate endpoints.