IL19 belongs to the IL-10 family of proinflammatory cytokines, which is composed of IL10, IL19, IL20, IL22, IL24, and IL26. IL19 is mainly expressed in monocytes and binds to the IL20 receptor complex which leads to the activation of the signal transducer and activator of transcription 3 (STAT3). It also performs up-regulation of IL6 and TNF-alpha and apoptosis induction, thus signifying its role in inflammatory responses.