Generation and characterization of the SCLC primary xenograft model. A, Outline of the experimental approach from primary sample, xenograft, cell line and secondary xenograft from the derived cell line. B, H&E stained section of mouse lungs following orthotopic injection of the LX22 xenograft. The “primary” tumor (T) and metastasis in mediastinal lymph node (LN) are highlighted. Scale bar = 1mm C, H&E stained section of the intrapulmonary tumor shown in B. Scale bar = 20μm.