Maspin: A Tumor Suppressing Serpin

Abstract
Maspin (mammary serpin) is a member of the serpin superfamily (Potempa et al. 1994). The gene was first identified by subtractive hybridization on the basis of its expression at the mRNA level in normal but not in tumor-derived mammary epithelial cells (Zou et al. 1994). The cloned and sequenced cDNA consists of 2584 nucleotides encoding a 42 kDa peptide with the overall structure of a serpin. Maspin has been localized to chromosome 18q21.3-q23 (Sager et al. 1994) closely linked to plasminogen activator inhibitor-2 (PAI-2), to BCL2, to the candidate tumor suppressor gene DCC (Sager et al. 1994), and to the candidate tumor suppressor gene SCCA (Schneider et al. 1995).