NCAM1 and small cell lung carcinoma: Those cell surface molecules, with great expression on the surface of SCLC cells, have been preferentially considered as potential therapeutic targets, such as CD47 and CD56.159,203 Delta-like ligand 3 (DLL3), which is an inhibitory Notch pathway ligand in over 80% of SCLC, upregulating and overexpressing in high-grade neuroendocrine tumors, whereas there is almost no expression in normal tissue, becomes an attractive therapeutic target.86,204 A phase I clinical trial adopting CAR-T cells with specificity targeting DLL3 (AMG 119) is currently ongoing (NCT03392064).