RB1 and lung carcinoma: Notably, in TP53- and RB1-inactivated lung cancer cell lines, inhibition of exportin 1 (XPO1) has been shown to prevent SCLC transformation and increase the efficacy of chemotherapy [158, 159].Additionally, histological transitions from other lung cancer types to SCLC may also be mediated by noncanonical integrin signaling through ITGB2 [160].