BAP1 and mesothelioma: In addition, although BAP1 loss and CDKN2A/p16 homozygous deletion have emerged as reliable markers for the differential diagnosis of benign mesothelial proliferation versus mesothelioma, they were revealed not to be appropriate for distinguishing mesothelioma from other malignant tumors [29,30,31,32,33,34,35,36].