Fig 1: Combined treatment with scFv-D4 and anti-PD-1 induces immune cell infiltration and shows remarkable anti-tumor activity in a 4T1/E2 breast cancer model.(a) Schematic representation of subcutaneous (s.c.) 4T1/E2 breast cancer cell treatments applied to BALB/c mice.(b, c) BALB/c mice (n = 7) were challenged s.c. with 106 4T1/E2 tumor cells. The mice were treated, as described in Figure 5(a), when the tumor size (diameter) reached 3–5 mm. Tumor growth (b) and survival (c) were recorded.(d–i) BALB/c mice (n = 5 with established 4T1/E2 tumors were treated as described in Figure 5(a). Tumors were isolated on day 34, and the immune cells were analyzed by flow cytometry. Shown are the numbers of tumor-infiltrating (d) CD45+CD3+CD8+ T cells and (e) CD45+CD11b+Gr1+ cells in the different treatment groups. The frequencies of CD44+CD127+ (f), LAG3+CD160+ (g), and PD1+ (h) cells among CD8+T-cell subsets, as well as PD1+ (i) cells among CD4+T-cell subsets, are shown.Data are representative of three experiments. Error bars represent standard error of the mean. *p < .05