In the U87MG tumor, FNR648-HSA was observed not only in the blood vessel regions, (Figure 4C; DAPI + CD31 + FNR648-HSA, and Figure S7A; FNR648-HSA as red signals) but also in the regions remote from the blood vessels (Figure 4D; DAPI + CD31 + FNR648-HSA and Figure S7B; FNR648-HSA as red signals). The gene discussed is PECAM1; the disease is neoplasm.