ITGAX and neoplasm: Indeed, immunohistochemical studies of lung tissues post inhalation of NP-DiR clearly showed that DiR signals were located primarily within CD11c+ APCs, and co-staining with anti-luciferase to label tumor cells further revealed that the NP-DiRs were distributed well intratumorally in individual metastases and engulfed by intratumoral CD11c+ APCs (Fig. 3d; Supplementary Fig. 5).