NRG1 and small cell lung carcinoma: As shown in Fig. 8C, primary immunodeficiency (NES = -1.57, P = 0.028), small cell lung cancer (NES = -1.45, P = 0.009), and phosphatidylinositol signaling system (NES = -1.4, P = 0.037) were enriched in the NRG1 low-expressed phenotype.