Seems to be involved in cell adhesion through trans-homophilic and -heterophilic interactions, the latter including specifically interactions with NECTIN1. Plays a role in the senescence-associated cell size enlargement via SFK/PI3K/Rac1 and thus promotes senescent cell survival. Participates also in the innate immune response by acting as a ligand for the receptor TIGIT to inhibit NK-cell activity