The HCK protein is a hematopoietic cell-dominated non-receptor tyrosine protein kinase that is critical for innate immune responses in neutrophils, monocytes, macrophages, and mast cells. HCK Protein, Human (Q523E, Q524E, Q525I, sf9, His) is the recombinant human-derived HCK protein, expressed by sf9 insect cells , with N-8*His labeled tag.