MSLN and cholangiocarcinoma: Moreover, MSLN is overexpressed in a variety of malignancies [19, 20], including (1) gynecologic cancers such as ovarian cancer [21–23], triple negative breast cancer (TNBC) [24–26], endometrial cancer [23, 27], and cervical cancer [23, 28]; (2) digestive system cancers such as pancreatic adenocarcinoma [21, 29–32], gastric carcinoma [21, 33, 34], and cholangiocarcinoma [5, 32, 35–37]; and (3) malignant pleural mesothelioma (MPM) [21, 25, 38–41], lung adenocarcinomas [23, 40–42] and some other squamous carcinomas of different sites of origin [5, 19] (Table 1).