“…The biological functions of Msln have been poorly understood because Msln-deficient mice do not show a detectable phenotype under physiological conditions [ 62 ]. On the other hand, Msln is known to be highly expressed in several human tumors including mesothelioma, ovarian cancer, pancreatic adenocarcinoma, lung adenocarcinoma, and cholangiocyte carcinoma [ 63 , 64 , 65 ], and thus it has attracted attention as a potential target for anti-cancer therapy [ 61 , 66 ] by newly developed strategies of immunotherapy using recombinant immunotoxin, antibody-drug conjugates, chimeric monoclonal antibody, and chimeric antigen receptor T cell therapy [ 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 ]. Msln expression is abundant in normal mesothelial cells, which are major components of the mesothelial layer lining parenchymal organs and serosal cavities [ 62 ].…”