L1CAM and small cell lung carcinoma: We demonstrated the following: (1) L1CAM is highly expressed in SCLC cell lines and tissues compared with lung adenocarcinoma (LUAD); (2) its expression is notable in the SCLC-N subtype [11,12]; (3) we have developed a novel anti-human L1CAM mAb, HSL175; and (4) HSL175-DT3C conjugates can induce SCLC-N cells to undergo apoptosis.