The present invention relates to a composition for priming a human Natural Killer (NK) cell. The present invention provides a natural killer (NK) cell priming composition which comprises (i) a CD2 ligation agent; (ii) an NKp46 ligation agent; and (iii) an LFA-1 ligation agent. The present invention also provides an NK-cell priming substrate which comprises (i) a CD2 ligation agent; (ii) an NKp46 ligation agent; and (iii) an LFA-1 ligation agent.