BCL2 and small cell lung carcinoma: In SCLC, a dual BCL-xL/BCL-2 PROTAC (753b) induced tumor regressions in NCI-H146 xenografts while avoiding dose-limiting thrombocytopenia, and an EZH2 PROTAC suppressed leptomeningeal metastases in chemoresistant SCLC mouse models [185,186].