Hematopoietic stem and progenitor cells give rise to various blood cell types, including red blood cells, platelet-producing cells, granulocytes, monocytes, T cells, B cells, and natural killer cells. The detailed functions of these cells will be explored in subsequent sections of the immunology course.

The hematopoietic stem cell (HSC) population maintains itself through self-renewal, ensuring a steady supply of blood cell types. Multipotent progenitors (MPPs) are an intermediary stage between HSCs and committed progenitors, with short-term and long-term MPPs showing varying self-renewal capacities. The differentiation pathways lead to lineage-committed progenitors like CMP, MEP, GMP, and CLP, giving rise to different blood cell lineages.

The "LSK" phenotype, consisting of cells expressing Sca-1 and c-Kit, was originally utilized to isolate hematopoietic stem cells (HSCs) in mice. However, further research has revealed the need for additional markers and functional assays to accurately identify and characterize true HSCs. Advanced technologies are aiding in the comprehensive study of HSC heterogeneity and lineage potential.