These analyses have revealed that a number of loss‐of‐function mutations present at low frequency in other cancer types are frequently identified during the development of PM, with two tumour suppressors most notably lost regularly in PM patients: BAP1, which acts as a deubiquitinase19, 20 and NF2, a major upstream activator of the core kinase module of the Hippo signalling pathway.21, 22. The gene discussed is BAP1; the disease is cancer.