FAP and neoplasm: Double immunofluorescence for FAP and adenovirus hexon protein showed that 80% of FAP+ cells were positive for hexon, indicating that FAP+ cells were efficiently infected with ICOVOR15 and probably supported virus replication (Fig. 5c–e), while the percent of infected GFP+ tumor cells (hexon/GFP double positivity) was lower (Fig. 5d, e).