Ready-to-use ELISA kits are available for the detection of p104, an alias of the protein, natural killer cell triggering receptor. The official gene symbol is NKTR. The protein, with a mass of 165.7 kDa and length of 1462 residues, is reported to be membrane-associated. It may be known by other names, including: p104, peptidyl-prolyl cis-trans isomerase NKTR, natural killer-tumor recognition sequence, natural killer triggering receptor, NK-TR protein, and NK-tumor recognition protein.