DLL3 and neoplasm: DLL3, on the other hand, has been at the forefront of many targeted therapies for SCLC, largely due to its tumor specificity, in which its cytoplasmic and cell surface expression contrast with its largely intracellular and restricted normal tissue expression (40, 41) Targeting DLL3, however, may pose a subtype-specific vulnerability as its expression may be preferentially associated with the SCLC A subtype because it is a direct transcriptional target of ASCL1 (42).