This gene encodes the beta subunit of casein kinase II, a ubiquitous protein kinase which regulates metabolic pathways, signal transduction, transcription, translation, and replication. The enzyme is composed of three subunits, alpha, alpha prime and beta, which form a tetrameric holoenzyme. The alpha and alpha prime subunits are catalytic, while the beta subunit serves regulatory functions. The enzyme localizes to the endoplasmic reticulum and the Golgi apparatus. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2013].