背景资料：SERPINB3(serpin peptidase inhibitor, clade B (ovalbumin), member 3), also known as SCCA1, increase in advancing stages of some cervical, lung, esophageal and head and neck cancers). Human chromosome position 18q21.3 contains a cluster of serpins, including a tandem duplication of the SCCA gene, plasminogen activator inhibitor type 2, and maspin. SCCA is transcribed by two nearly identical genes (SCCA1 and SCCA2), and is mainly produced as SCCA1. The human SCCA1 gene encodes a 390 amino acid protein that was originally isolated from a metastatic cervical squamous cell carcinoma.