SF2/ASF is a member of the Ser-Arg-rich (SR) protein family of highly conserved nuclear phosphoproteins involved in pre-mRNA splicing. Besides its role in nuclear pre-mRNA splicing, SF2/ASF has been shown to shuttle between the nucleus and cytoplasm, suggesting additional roles in mRNA transport and cytoplasmic events. SF2/ASF associates with translating ribosomes and stimulates translation. It also activates translation initiation by suppressing the activity of 4E-BP1, which is mediated by SF2/ASF association with mTOR and the phosphatase PP2A. More recent studies have demonstrated a role for SF2/ASF in microRNA processing. Synonyms: ASF, MGC5228, SF2, SF2p33, SRp30a