KLRD1 and neoplasm: Numerous NK cell receptors have been identified to date, including the CD94/NKG2 receptor family, which encompasses inhibitory receptors like NKG2A and activating receptors such as NKG2C and NKG2D, as well as the natural cytotoxicity receptors (NCRs), which include the receptors NKp30, NKp44, and NKp46, involved in the recognition of tumor cells.