Fig. 1

A Developmental pathway of NK cells. The developmental pathway of NK cells from the bone marrow involves an ongoing process of differentiation and maturation. It begins with hematopoietic stem cells (HSCs) residing in the bone marrow, which serve as the origin for NK cell development. Firstly, HSCs differentiate into Lymphoid-primed Multipotent Progenitors (LMPPs). Subsequently, LMPPs give rise to Common Lymphoid Progenitors (CLPs), which possess the ability to develop into various lymphoid lineages, including NK cells. Following the emergence of NK cell progenitors from CLPs, the developmental process continues onward. Subsequently, these NK cell progenitors undergo further differentiation, resulting in the formation of mature NK cells. These mature NK cells are identifiable by their expression of CD56 and CD16. B In vitro, human NK cells can differentiate into two distinct functional subsets known as NK1 and NK2. When cultured with IL-12 and IL-18, NK cells (NK1) primarily generate IFN-γ, while those cultured with IL-4 (NK2) predominantly produce IL-5 and IL-13. C Human NK cells can be categorized into three distinct functional subsets based on their roles, specifically referred to as NK tolerant, NK cytotoxic, and NK regulatory. Figure created using BioRender (Created with biorender.com)