IL15 and neoplasm: A pioneering study revealed that human IL‐15 gene‐modified NKL cells (NKL‐IL‐15) could increase the susceptibility of HCCs to NKL‐mediated cytolysis via the expression of cytolysis‐related molecules (NKp80, TRAIL, granzyme B, IFN‐γ and TNF‐α) and the induction of NKG2D ligand overexpression on tumour cells.72