The protein encoded by this gene is an RNA-binding nuclear protein that is a tumor-rejection antigen. This antigen possesses tumor epitopes capable of inducing HLA-A24-restricted and tumor-specific cytotoxic T lymphocytes in cancer patients and may be useful for specific immunotherapy. This gene product is found to be an important cellular factor for HIV-1 gene expression and viral replication. It also associates transiently with U6 and U4/U6 snRNPs during the recycling phase of the spliceosome cycle. This encoded protein is thought to be involved in the regulation of mRNA splicing. [provided by RefSeq, Jul 2008].