To get an idea whether miscellaneous cell targeting might explain tumor heterogeneity in the current lung cancer model we conduced immunohistochemical staining for club cell protein 10 (CC10) and surfactant protein C (SPC) predicted to label – based on the natural expression pattern (Figures S5A–S5C) – bronchiole- and alveolar type 2 (AT2)-derived BRAF mutant cells, respectively. The gene discussed is BRAF; the disease is lung cancer.