BTN3A1 and neoplasm: Following phosphoantigen binding to the intracellular B30.2 domains of BTN3A1 in tumor cells, BTN3A1 undergoes a conformational change (Sandstrom et al., 2014; Gu et al., 2017) and promotes the interaction between BTN2A1 and BTN3A1 intracellular domains (Rigau et al., 2020).