To further ensure that [18F]FBNAF could bind to STAT3 in vivo, we performed ex vivo autoradiography using sections prepared from the excised tumors of A549 tumor-bearing mice at 30 min postinjection of [18F]FBNAF and compared the results with that of immunohistochemical analysis of an adjacent section (Fig. 6, Supplementary Fig. S3). Here, STAT3 is linked to neoplasm.