pro-NK cell pro-natural killer cell preNK cell Most markers only described for human pro NK cells. A lymphoid progenitor cell that is committed to the natural killer cell lineage, expressing CD122 (IL-15) receptor, but lacking many of the phenotypic characteristics of later stages of natural killer cell development such as expression of NK activating and inhibitory molecules. In human this cell has the phenotype CD34-positive, CD45RA-positive, CD10-positive, CD117-negative, and CD161 negative. NKP natural killer cell progenitor ZFA:0009348 null cell lymphoid lineage restricted progenitor cell