CD226 and neoplasm: Natural killer cells (NK cells), important immune cells in the organism, are morphologically large granular lymphocytes, and although they lack tumor antigen-specific cell surface receptors, they have a number of alternative receptors that can recognize cancer cells, including NKG2D (Dhar and Wu, 2018; Liu et al., 2019), NKp44, NKp46, and DNAM-1,(Horton and Mathew, 2015; Liu et al., 2019; Focaccetti et al., 2022; Murayama et al., 2022; Cifaldi et al., 2023) which have excellent biocompatibility and tumor targeting properties.