Negative regulation of cytokine signaling.

Immune and inflammatory systems are controlled by multiple cytokines, including interleukins and interferons. Many of these cytokines exert their biological functions through Janus kinases and signal transducers and activators of transcription factors. The cytokine inducible SH2 protein (CIS) and suppressors of cytokine signaling (SOCS) are members of a family of intracellular proteins, several of which have emerged as key physiological regulators of cytokine-mediated homeostasis, including innate and adaptive immunity. This article focuses on the molecular mechanism of the action of CIS/SOCS family proteins and their roles in immune regulation and inflammatory diseases.