CTLA4 and neoplasm: Central memory (Tcm) and effector memory (Tem) CD4pos and CD8pos T cells displayed reduced levels of T cell exhaustion and inhibitory markers such as LAG3 (Fig. 5h, i), CTLA4 and PD-1 (Fig. 5i), consistent with improved function of memory CD4pos and CD8pos T cell populations in Osm−/− tumours (Fig. 5h, i and Supplementary Fig. 6i).