SFTPC and neoplasm: Notably, tumor morphology and location in the alveolar compartment were strikingly similar in all mice, and no tumors arose from airways or BOA lesions (Fig. 6D, 6E and Fig. S1A) To further examine the properties of lung tumors, we performed IHC by using the Clara cell marker CC10 and type II cell marker surfactant protein C (Pro-SPC).