Abstract: Aspects of the present disclosure are directed to methods for classification and treatment of small cell lung cancer (SCLC). Certain aspects pertain to treatment of a subject having SCLC using a targeting agent for a cell surface protein, where a targeting agent is selected based on a subtype classification of the SCLC. Disclosed are methods for identifying a subject as having an SCLC subtype (e.g., SCLC-A, SCLC-N, SCLC-P, SCLC-I) and administering a targeting agent configured to target a cell surface protein associated with the identified SCLC subtype. Also disclosed are compositions comprising targeting agents for treatment of SCLC.