PTGIS and mesothelioma: Of the 10 candidate biomarkers identified in the study, several have previously been associated with the mesothelial lineage or mesothelioma, these include the prototype mesothelial lineage marker mesothelin (Msln)[15] and others such as uroplakin 3B(Upk3b) [35], prostaglandin I2 (prostacyclin) synthase (Ptgis) [39] and insulin-like growth factor binding protein 6 (Igfbp6) [40].