This gene encodes an NADPH sensor protein that preferentially binds to NADPH. The encoded protein also negatively regulates the activity of NF-kappaB in a ubiquitylation-dependent manner. It plays a key role in cellular antiviral response by negatively regulating the interferon response factor 3-mediated expression of interferon beta. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, Feb 2015].