PRF1 and neoplasm: Similarly, the scIgG containing tumors had significantly lower perforin levels measured using immunofluorescence (IF) imaging, when compared with their control tumors in both xenograft human tumor model (Fig. 4e and Supplementary Fig. S4e) and 4T1-IdeS syngeneic murine tumor model (Fig. 4f and Supplementary Fig. S4f).