MSLN and mesothelioma: Several generations of immunotoxins, such as SS1P and LMB100, were engineered by conjugation of anti-human MSLN SS1 Ab (Hassan et al., 2007; Hassan et al., 2014) to PE38 (truncated Pseudomo-nas exotoxin, that causes cellular apoptosis) (Hassan et al., 2000), and successfully tested in clinical trials in patients with mesothelioma, ovarian cancer and pancreatic cancer (Liu et al., 2012; Kreitman et al., 2009; Chowdhury and Pastan, 1999; Alewine et al., 2014))(https://clinicaltrials.gov/ct2/show/NCT02810418) (Hassan et al., 2007; Hassan et al., 2014; Kreitman et al., 2009).