IL-3 acts on which hematopoietic precursors?

IL-3 acts on which hematopoietic precursors?

• A. Lymphoid precursors
• B. Myeloid precursors
• C. Erythroid precursors
• D. All of the above

Answer: (D)

IL-3 is a multipotent hematopoietic growth factor that acts on early progenitors in the bone marrow, promoting their proliferation and differentiation into multiple lineages. Because it targets pluripotent progenitors capable of giving rise to erythroid, myeloid, and lymphoid cells, IL-3 supports development across these lineages rather than a single path. That breadth explains why the best choice is all of the above: IL-3 can stimulate erythroid and myeloid precursors directly, and the upstream progenitors it acts on can also generate lymphoid cells under the right conditions. For contrast, other cytokines tend to be more lineage-restricted—erythropoietin for erythroid cells, GM-CSF or G-CSF for myeloid cells, and IL-7 for lymphoid development— highlighting IL-3’s broad role in early hematopoietic progenitors.

IL-3 is a multipotent hematopoietic growth factor that acts on early progenitors in the bone marrow, promoting their proliferation and differentiation into multiple lineages. Because it targets pluripotent progenitors capable of giving rise to erythroid, myeloid, and lymphoid cells, IL-3 supports development across these lineages rather than a single path. That breadth explains why the best choice is all of the above: IL-3 can stimulate erythroid and myeloid precursors directly, and the upstream progenitors it acts on can also generate lymphoid cells under the right conditions. For contrast, other cytokines tend to be more lineage-restricted—erythropoietin for erythroid cells, GM-CSF or G-CSF for myeloid cells, and IL-7 for lymphoid development— highlighting IL-3’s broad role in early hematopoietic progenitors.