The new cell line (Nakata-1) was established from squamous cell carcinoma of the buccal mucosa. IL-1 activity was found in its culture supernatants by thymocyte proliferation assay and fibroblast proliferation assay. This activity revealed the same behavior as that of human macrophage IL-1 in gel filtration chromatography. This activity, therefore, is thought to be attributed to the so-called “IL-1 like factor.”
