This gene encodes a member of the HEXIM family of proteins. This protein is a component of the 7SK small nuclear ribonucleoprotein. This protein has been found to negatively regulate the kinase activity of the cyclin-dependent kinase P-TEFb, which phosphorylates multiple target proteins to promote transcriptional elongation. This gene is located approximately 7 kb downstream from related family member HEXIM1 on chromosome 17. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2015].