HCC1 is a member of the U2AF65 family of proteins. The encoded protein is found in the nucleus, where it co-localizes with core spliceosomal proteins. It has been shown to play a role in both steroid hormone receptor-mediated transcription and alternative splicing, and it is also a transcriptional coregulator of the viral oncoprotein v-Rel. Multiple transcript variants have been observed for this gene. A related pseudogene has been identified on chromosome X. [provided by RefSeq, Aug 2011].