IL2 and neoplasm: We have previously shown that local intra-tumoral administration of IL-2/anti-CD40 immunotherapy induces mesothelioma tumor regression in young (aged 2–3 months) female C57BL/6J mice (Jackaman et al., 2008, 2016; Jackaman and Nelson, 2012); mediated primarily by neutrophils, CTLs and macrophages.