Flow cytometry was employed to verify the varying levels of CD38 expression by the lung cancer cell lines. Daratumumab served as the primary antibody, at a concentration of 20 μg of antibody per 1 mL of solution, while goat anti-human AlexaFluor488 secondary antibody was utilized. Proper controls of cells alone, primary antibody alone, secondary antibody alone, and a nonspecific IgG antibody were employed. Staining and flow cytometry analysis followed standard protocols.24 (link) Analysis was performed using the MACSQuant cytometer and FlowJo (V.10) software.