"Cytokines (Greek:Cyto from Greek \"\u03BA\u03CD\u03C4\u03C4\u03B1\u03C1\u03BF\" kyttaro \"cell\" + Kines from Greek \"\u03BA\u03AF\u03BD\u03B7\u03C3\u03B7\" kinisi \"movement\") are a broad and loose category of small proteins (~5\u201320 kDa) that are important in cell signaling. They are released by cells and affect the behavior of other cells. Cytokines can also be involved in autocrine signaling."@en . .