NOTCH1 and mesothelioma: Activation of Notch1 in mesothelioma specimens has been previously reported by Graziani et al. (2008), which also showed that in mesothelioma cell lines Notch1 promotes cell proliferation and activates the pro-survival phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway by inhibiting PTEN.