__________ play a role in hematopoiesis and in activating adaptive and innate immune responses.ANSWERInterleukinsInterferonsTumor necrosis factorsChemokines

Interleukins, Interferons, Tumor necrosis factors, and Chemokines all play a role in hematopoiesis and in activating adaptive and innate immune responses.

1. Interleukins: These are a group of cytokines that were first seen to be expressed by white blood cells (leukocytes). They play a crucial role in cell communication during immune responses and stimulate the growth and differentiation of T cells, B cells, and hematopoietic cells.

2. Interferons: These are a group of signaling proteins made and released by host cells in response to the presence of several viruses. They allow for communication between cells to trigger the protective defenses of the immune system that eradicate pathogens or tumors.

3. Tumor necrosis factors: These are a group of cytokines that can cause cell death (apoptosis). They are involved in systemic inflammation and are produced chiefly by activated macrophages, although they can be produced by many other cell types such as CD4+ lymphocytes, NK cells, neutrophils, mast cells, eosinophils, and neurons.

4. Chemokines: These are a family of small cytokines, or signaling proteins secreted by cells. Their name is derived from their ability to induce directed chemotaxis in nearby responsive cells. They are chemotactic cytokines which play a crucial role in inducing leukocyte migration to sites of infection or inflammation.