CD244.2 protein, also known as natural killer cell receptor 2B4 isoform 2 precursor, is a type-I transmembrane protein belonging to the signaling lymphocytic activation molecule (SLAM) family. It is encoded by the CD244 gene and primarily expressed in various immune cells such as NK cells, T cells, monocytes, eosinophils, myeloid-derived suppressor cells, and dendritic cells. This protein mainly binds to its ligand CD48, another SLAM family member, to transmit stimulatory or inhibitory signals and regulate immune responses, including NK cell-mediated cytotoxicity, leukocyte activation, and cytokine production. CD244.2 plays a crucial role in the immune system and has potential as a therapeutic target in cancer and other immune-related diseases.