The functional integrity of the h1567 minibody was also shown by its potent in vivo anti-tumor and in vitro killing activities. In the first treatment study (model 1), marked inhibition of Mac-1 tumor cell growth and increased survival was seen (Figure 2a and b ) even though these SCID-BEIGE mice have profound immune cell defects including lack of T and B cells as well as impaired macrophage and NK cell effector functions [26] . Further IHC staining of the paraffin-embedded tumor tissues revealed a predominant infiltration of Ly-6G + CD16A + neutrophils only in the h1567 minibody but not control 11A minibody treated mice (Figure 2c) . Furthermore, in vitro ADCC assay using purified mouse neutrophils as an effector cells demonstrated that h1567 induced significant lysis of CCR4 + Mac-1 cells, while no lysis was seen with 11A ( Figure 2e) . These results support the view that neutrophil-mediated ADCC is involved in anti-tumor activities following AAV8-h1567 gene delivery in the SCID-BEIGE CTCL mouse model.