Currently, there are multiple engineered cytokine therapeutics undergoing clinical trials, including plasmid and mRNA therapeutics for optimized cytokine expression, mainly targeting auto-immune diseases and metastatic solid tumors, as well as cell therapies, such as IL-12 expressing TCR-T cells and IL-15 expressing CAR NK cells for refractory carcinomas and lymphoid tumors [39]. This evidence concerns the gene IL15 and immune system disorder.