After i.v. injection of 32 into 4T1 tumor-bearing mice pretreated with PBS or IFN-γ, the 660 nm–excited NIR-II signal increased continuously over 24 h in IFN-γ–treated tumor models, yielding a FL660Ex/FL808Ex ratio of 1.71 at 24 h post-injection of IFN-γ—approximately 1.39-fold higher than in PBS controls (Figure 39b). This evidence concerns the gene IFNG and neoplasm.