IFNG and neoplasm: IL-18 is a cytokine characterised as an inducer of IFN-γ expression in T cells139 and has been shown to activate monocytes and lymphocytes without causing severe toxicity in clinical trials.140 Recently, two studies revealed that inducible expression of IL-18 in CAR T cells enhances proliferation and anti-tumour activity of monocytes and lymphocytes.141,142 Interestingly, IL-18-producing TRUCK T cells induced acute inflammatory reactions and altered the balance of pro-inflammatory and anti-inflammatory cells in established, large pancreatic and lung tumours.