CDKN2A and mesothelioma: Recent research has revealed that mesotheliomas frequently exhibit loss of BAP1, which is more common in the epithelioid subtype, and/or loss of CDKN2A, which is relevant to the differential diagnosis of the epithelioid subtype versus mesothelial hyperplasia and sarcomatoid subtype versus reactive fibrous pleuritis (more common in sarcomatoid subtype).