SERPINB4 and inverted papilloma: Yasumatsu, et al.21 (2001) found that normal keratinocytes had more SCCA1 than head and neck SCC cells, and that the SCCA1 level was significantly higher than the sinonasal SCC level in both tissue and serum expression in inverted papilloma.24To the best of our knowledge, this study is the first to compare SCCA1 in verrucous carcinoma and benign hyperplasia of oral epithelium with SCCA1 in oral SCC.