Norepinephrine is a critical regulator of hematopoietic stem activity.

Sub-thermoneutral temperatures activate the sympathetic nervous system to suppress tumor immunity and promote tumor growth.

Macrophage NE production is implicated in fat metabolism.

Catecholamines regulate lymphocyte emigration from lymph nodes.

The sympathetic nervous system is the efferent arm of reflexes that dampen immune and inflammatory responses.