Used in targeted cancer therapies, particularly for small cell lung cancer (SCLC). Binds specifically to DLL3 protein expressed on tumor cells, enabling precise delivery of cytotoxic agents when conjugated to drugs. Supports development of antibody-drug conjugates (ADCs) for improved tumor cell killing with reduced damage to healthy tissues. Investigated in clinical trials to evaluate efficacy in relapsed or refractory neuroendocrine tumors. Also serves as a reference standard in immunoassays and biomarker studies to measure anti-DLL3 antibody performance and expression levels in patient samples.