Subcellular expression of maspin – from normal tissue to tumor cells

Table 2 Maspin expression in organs of the respiratory and gastroenteropancreatic system

Organ/ tissue	Subcellular expression in normal tissue	Subcellular expression in pathologic conditions
Lung	Bronchial basal cells: Nuclear staining; Alveolocytes: Negative	Non-small cell carcinomas: Cytoplasm only: Negative prognostic factor; Nucleus only: Low aggressivity
Esophagus	Squamous epithelium: Negative or weak cytoplasm	SCC: Nucleus: Low pTNM stage; Cytoplasm: Risk for lymph node metastases
Stomach	Foveolar and glandular cells: Cytoplasm or negative	Dysplasia: Nucleus: High-grade dysplasia; Carcinomas: Cytoplasm: Better prognosis; Nuclear: Local aggressive behavior; Negative: Risk for distant metastases or neuroendocrine component
Colon and rectum	Normal mucosa: Cytoplasm or negative	Dysplasia: Nucleus: High-grade dysplasia; Adenocarcinoma: Cytoplasm only: Low-grade tumor, low risk for metastases, high chance for MSI-H status; Nuclear only: High pTNM stage, high-grade budding; Negative: Risk for distant metastases or neuroendocrine component
Liver and intrahepatic biliary ducts	Negative in most of the normal hepatocytes and in normal biliary ducts	Carcinoma: Positive (cytoplasmic, nuclear or mixed cyto-nuclear expression), with unknown significance
Pancreas	Negative in exo- and endocrine pancreas	PanIN grade 1 and grade 2: Negative; PanIN grade 3 and PDAC: Positive (cytoplasmic and nuclear staining); Endocrine tumors: Negative; Ductal adenocarcinoma: Nuclear
Gallbladder	Negative or positive (cyto-nuclear staining)	Dysplasia: Negative or weak staining; BilIN, carcinoma: Cyto-nuclear expression gradually increases from normal epithelium to BilIN and carcinoma

BilIN: Biliary intraepithelial neoplasia; MSI-H: High microsatellite instability; PanIN: Pancreatic intraepithelial neoplasia; SCC: Squamous cell carcinoma; PDAC: Pancreatic ductal adenocarcinoma