We have systematically studied the core transcriptional deregulation in three well-characterized lung cancer subtypes (LUAD, LUSC and SCLC), and identified a number of common (e.g. proliferation-related E2F1 and TCF3) as well as subtype-specific TF circuits (e.g. the epithelial-development-related TP63/SOX2/DMRT3 module in LUSC, the EMT-related LEF1/MSC module in LUAD, and the neural differentiation regulator ASCL1 in SCLC). The gene discussed is ASCL1; the disease is lung cancer.