SPP1 and mesothelioma: Identification of a potential biomarker for mesothelioma is another subject of current research.10 11 Soluble mesothelin-related peptide (mesothelin) has the greatest sensitivity and specificity in the diagnosis of mesothelioma compared with a number of other markers such as fibulin-3, osteopontin and megakaryocyte potentiating factor.12–14 Despite studies demonstrating an elevated mesothelin level at presentation of patients with MPM, its role in the diagnostic arena is yet to be established.