ASCL1 and small cell lung carcinoma: Cancer cells undergo lineage plasticity to adapt, survive therapy, grow, and metastasize.63 NOTCH-induced transition of NE to non-NE cells occurred in ex vivo cultures of an ASCL1 subtype CDX, which was required for VM (Fig. 3), validating the SCLC plasticity seen in GEMMs.9-11 Non-NE CDX cells formed hollow tubules on Matrigel with a lumen diameter supportive of erythrocyte transit that closely resembled structures formed by HUVECs under identical conditions (Fig. 3).