In order to maximize the diagnostic sensitivity and specificity of immunohistochemical markers, Bernardi et al. [93] demonstrated that the coordinated use of two mesothelial negative biomarkers, namely claudin 4 and BAP1, had the best performance in differential diagnosis between epithelioid or biphasic mesothelioma and metastatic carcinomas. The gene discussed is BAP1; the disease is metastatic carcinoma.