We performed cancer immunotherapy using three different cytokine genes: interleukin 12 (IL12) and newly designed secreted isoforms of tumour necrosis factor‐α (TNFα) and interleukin 15 (IL15), as they have been shown to produce potent, cell‐mediated anti‐tumour effects (Otani et al, 1999; Johansson et al, 2012; Waldmann et al, 2020). The gene discussed is IL15; the disease is cancer.