A strong background fluorescence of the skin and organs of the mice was peculiar, whereas the tumor fluorescence reached a maximum already at 4 h and 8 h post injection for the Bi-FAP/mEnd-IL and mEnd-IL respectively (Figure 6A,B, Bis-IL and mEnd-IL), with the Bi-FAP/mEnd-IL group giving higher tumor signals than the mEnd-IL group (Figure 6B,C, Bis-IL). This evidence concerns the gene FAP and neoplasm.