RT has shown other immunomodulatory effects that could also be synergistic when combined with immunotherapy, including the following: enhanced MHC class I expression [53], which allows for better recognition of the tumour cell by T lymphocytes; upregulation of FAS receptors in the tumour cells, leading to greater infiltration of these cells by T lymphocytes [54]; increased expression of NKG2D ligands, which allows for greater action of natural killer cells [55]; and other effects currently under investigation. Here, KLRK1 is linked to neoplasm.