Heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is a member of the hnRNP A/B family of related RNA binding proteins that bind pre-mRNA and are involved in the processing, metabolism and transport of nuclear pre-mRNA transcripts . hnRNP A1 regulates the alternative splicing of c-Src, c-H-Ras and modifies initiation of translation of the fibroblast growth factor 2 mRNA. hnRNP A1 expression level is elevated in many cancers; knockdown of hnRNP A1 leads to apoptosis in various cancer cells . Although predominantly nuclear, hnRNP A1 is continually transported from the nucleus to the cytoplasm where it disassociates from mRNA and is rapidly re-imported into the nucleus . hnRNP A1 binds to cis-acting repressive sequences (CRS) of HIV-1 to influence HIV-1 production . HIV-1 enhances hnRNP A1 expression and promotes the relocalization of hnRNP A1 to the cytoplasm ,