Hematopoiesis, from one stem cell to every mature line.

Kidney-derived hormone; drives erythroid survival, proliferation, and maturation. Increases with hypoxia.

Liver-dominant cytokine; principal regulator of megakaryocyte growth and platelet production; also supports HSCs.

Neutrophil lineage expansion and maturation; clinically used for neutropenia and stem-cell mobilization.

Granulocyte–monocyte progenitor support; promotes granulocyte and monocyte/DC production.

Monocyte/macrophage lineage commitment and survival.

Early multipotent progenitor support; especially linked with basophil development in exam associations.

Signature eosinophil growth, differentiation, and activation cytokine.

Key lymphoid progenitor and B/T lymphopoiesis signal; T cells complete maturation in the thymus.

Critical for NK-cell development, survival, and homeostatic proliferation.

B-cell survival and maturation factor, especially beyond the earliest marrow stages.

Early stem/progenitor maintenance and expansion; FLT3L strongly supports early lymphoid/DC compartments.

T-cell activation and proliferation; also supports NK-cell expansion after activation.

“Every RBC needs EPO; every platelet needs TPO; every neutrophil needs G-CSF; every eosinophil remembers IL-5.”

Neutrophils are the first responders to acute bacterial inflammation. Eosinophils point toward parasites and type-2 hypersensitivity. Basophils are rare circulating cells; mast cells are tissue-resident.

Monocyte is the circulating form; macrophage is the differentiated tissue form. Do not treat them as identical compartments.

B cells mature into antibody-secreting plasma cells and memory B cells after activation. Plasma cells are the antibody factory—not the antigen-presenting “default” endpoint.

CLP gives a precursor, but T-cell maturation is thymus-dependent. Think positive/negative selection, then CD4 or CD8 lineages.

Platelets are cytoplasmic fragments shed from megakaryocytes, not complete nucleated cells.