BAP1 and neoplasm: Although Cre-mediated deletion of any pair of homozygous alleles sufficed to give rise to pleural mesothelioma, acquired loss of BAP1 protein expression was found in the majority of Nf2fl/fl;Cdkn2afl/fl tumours in vivo, and homozygous deletion of all three genes was required for spheroid formation in vitro (Kukuyan et al., 2019).