We have previously shown that CD26 was also highly expressed in various pathologic types of malignant mesothelioma, including localized malignant mesothelioma, well-differentiated papillary malignant mesothelioma, and diffuse malignant mesothelioma[16], and the specific staining of malignant meshothelioma cells was also observed with the use of the anti-CD26 pAb (Figure 3A-ii). This evidence concerns the gene DPP4 and malignant mesothelioma.