GPC1 and malignant epithelioid mesothelioma: One study showed that the GPC1 protein expression was detected by immunohistochemistry (IHC) in all 33 cases of mesotheliomas and 20 out of 21 cases of lung adenocarcinoma [22], whereas the IHC result obtained from another study showed that GPC1 was expressed in all 82 cases of epithelioid mesothelioma, but only 3 out of 97 cases of lung adenocarcinoma [23].