Given that our choice of using ASCL1 and NEUROD1 to cluster SCLC cell lines was based on experimental data, we conducted an unbiased analysis of using any 2 of 33 possible nodes for characterization (i.e. 33C2 = 528 combinations) in their ability to define four SCLC phenotypes. Here, NEUROD1 is linked to small cell lung carcinoma.