Human NK cells are CD3⁻CD56⁺NKp46⁺. Shown is a representative example of immunophenotypic analysis from a healthy donor when gating on peripheral blood lymphocytes. NK cells lack expression of CD3 and coexpress CD56 and NKp46. The left and middle dot plots were gated on total lymphocytes using forward scatter versus side scatter parameters. The dashed line in the left dot plot separates CD56^dim from CD56^bright NK cells. The arrows in the middle plot indicate a few CD3⁺ cells that coexpress NKp46. The right dot plot is gated on CD3⁻ lymphocytes and demonstrates the 2 major NK-cell populations in the blood: CD56^brightNKp46^bright and CD56^dimNKp46^dim. The arrow in the first quadrant of the right dot plot highlights a few CD56^dim NK cells that likely lack expression of NKp46.