这个基因编码酪氨酸激酶的一个成员，更具体地说，是janus激酶（jaks）蛋白家族。该蛋白与I型和II型细胞因子受体的胞质结构域相关，并通过磷酸化受体亚单位释放细胞因子信号。它也是I型和III型干扰素信号通路的组成部分。因此，它可能在抗病毒免疫中发挥作用。该基因突变与高免疫球蛋白e综合征（hies）有关，hies是一种以血清免疫球蛋白e升高为特征的原发性免疫缺陷。
This gene encodes a member of the tyrosine kinase and, more specifically, the Janus kinases (JAKs) protein families. This protein associates with the cytoplasmic domain of type I and type II cytokine receptors and promulgate cytokine signals by phosphorylating receptor subunits. It is also component of both the type I and type III interferon signaling pathways. As such, it may play a role in anti-viral immunity. A mutation in this gene has been associated with hyperimmunoglobulin E syndrome (HIES) - a primary immunodeficiency characterized by elevated serum immunoglobulin E. [provided by RefSeq, Jul 2008]