IL2 and neoplasm: We also assessed T-cell effector functions and, whilst no statistically significant alterations in the number of granzyme B, IFN-γ or TNF-α-positive CD8+ T cells were detected (Fig. EV4A–C), significantly increased numbers of IL-2+ CD8+ T cells were observed in the lungs of tumour-bearing MMTV-PyMT mice lacking Upp1 (Fig. 4C).