The human genome encodes three vaccinia-related kinases (VRK1, VRK2, and VRK3). VRK3 has a degraded ATPbinding site and is thought to be a pseudo-kinase, while VRK1 and VRK2 have active kinase domains and have been associated with various cellular processes, including cell replication, chromatin remodeling, and response to DNA damage. VRK2 has two isoforms that share identical kinase domains but locate to distinct cellular compartments: endoplasmic reticulum (VRK2A); and cytoplasm and nucleus (VRK2B). VRK1 can be found in both nucleus and cytoplasm. Genetic studies have associated VRK1 and VRK2 with a number of human diseases and conditions. VRK2 is associated with neurological disorders, such as schizophrenia, multiple sclerosis, major depressive disorder, and epilepsy. VRK1 overexpression is associated with increased cell division and poor prognosis in a number of cancers. Despite these advances, our understanding of the cellular roles of human VRKs and their therapeutic potential is limited. Currently, there are no potent or specific small molecule inhibitors of the VRKs.