KRT5 and pleural neoplasm: Another two cases, both with a predominant pleural tumor mass (patient 4 and 7), were initially classified as mesothelioma, although all mesothelial markers such as calretinin, WT1, D2-40 and CK5/6 tested negative and BAP-1 and MTAP were retained (Table 2 and Supplementary Table 3).