MSLN and cancer: Three classes of potential Msln inhibitors have been generated and potentially used to block MSLN-MUC16-THY-1 signaling pathway in patients: anti-human MSLN Ab-immunotoxin (that causes death of human MSLN+ cancer cells) (Hassan et al., 2007); anti-MSLN blocking Abs can potentially suppress growth and proliferation of aPFs (Onda et al., 2005); or recombinant human soluble THY1 (hsTHY1, that neutralize reactivity to αν-β5 integrins, and bind to TGFβRI to prevent MSLN signaling) (Tan et al., 2019).