Clinical trials combining either LSD1 or EZH2 chemical inhibitors with SCLC-centric cytotoxic chemotherapy may have seemed logical based on preclinical mechanism;177 however, two points of caution should be raised based on current trial results — (1) toxicity may be limiting, and thus preclude the combination of certain cytotoxic chemotherapies with EZH2 catalytic inhibitors,178 and (2) if LSD1 inhibition does suppress an Ascl1-dependent transcriptional program, then this may also suppress the chemotherapy-sensitive NE fraction, limiting activity. Here, EZH2 is linked to small cell lung carcinoma.