CXCL8 and cardiac arrest: Cytokines, including interleukin 6 (IL6), interleukin 8 (IL8), soluble receptor of interleukin 2 (sIL2R), and tumor necrosis factor alpha (TNF-alpha), are key mediators of the inflammatory response.10, 11 IL6 and TNF- alpha are pleiotropic cytokines critically involved in the systemic inflammatory response following cardiac arrest, with IL-6 reflecting the magnitude of tissue injury and TNF-α may contributing to hemodynamic instability.