STAT3 and neoplasm: In order to substantiate the findings of our mouse model, we analysed the human AC xenograft samples and found that tumours lacking STAT3 showed significantly increased numbers of infiltrating CD11b+Gr1+ and CD11b+ F4/80+ cells (Fig. 2g) and were significantly more vascularized (Fig. 2h), thus confirming our observations in the murine model.