NPC2 and cancer: In comparison to ciliated, Club/Clara cells, pulmonary alveolar type 1 (AT1) and pulmonary alveolar type 2 (AT2) (Fig. 8d), the EGFRex19 cancer cell cluster was characterized by high expression of NPC2 and surfactant genes SFTPB, SFTPC, and SFTPD (Supplementary Data 26 and 27).