Ren HZ, et al. - Since it remains unclear in the literature if c-MET, a receptor tyrosine kinase, is also expressed in benign mesothelial reactions, and therefore, researchers investigated if c-MET immunohistochemistry can distinguish benign from malignant mesothelial processes. A 12-point H-score, to assess membrane staining for c-MET, was employed and classified as negative (score = 0), trace (score = 1–3), moderate (score = 4–6), and strong (score = 8–12). In 24 of 45 (53%) epithelioid malignant mesotheliomas (EMMs), the H-score was identified to be > 3 (moderate or strong). A rise in sensitivity to 75% was brought about by adding BAP1 staining to the c-MET–negative/trace EMM, whereas similar addition of MTAP (methylthioadenosine phosphorylase) staining rose sensitivity to 77%. Overall, it was inferred that a diagnosis of EMM vs an epithelial reactive proliferation can be supported by using moderate/strong c-MET staining. Experts also concluded that c-MET is too insensitive to use for identifying SMM (sarcomatoid/desmoplastic mesothelioma).