Two new, good growing cell lines (GLC-8, GLC-11) have been established from biopsies of small cell lung cancer (SCLC). Tumor biopsies were procured by rigid bronchoscopy from tumor recurrences at the site of the primary lesions. Both tumors were clinically resistant to chemotherapy. Cytogenetic analysis revealed deletions in the short arm of chromosome 3. GLC-8 shows amplification of N-myc. Both cell lines show SCLC differentiations; neurosecretory granules were present and the SCLC related hormones dopa-decarboxylase and creatine kinase were elevated. Both cell lines behave as so-called 'classic' SCLC cell lines.