BAP1 and mesothelioma: BAP1 loss-of-function mutations are present in families predisposed to mesothelioma and in 60% of patients with sporadic mesothelioma.4 As BAP1 is implicated in many cellular processes, including DNA repair and apoptosis, its mutation may act in co-operation with environmental exposure to asbestos to drive MPM carcinogenesis.1,2,5,6 While MPM arising in the context of germline BAP1 mutations occurs in younger patients and is characterised by a better prognosis, sporadic MPM is in most cases refractory to therapy.7–9