UBE2I and viral infectious disease: During viral infection, IRTKS can recruit ubiquitin-conjugating enzyme 9 (Ubc9) to SUMOylate PCBP2 within the cell nucleus, leading to cytoplasmic translocation of PCBP2 and then triggering degradation of the mitochondrial adapter MAVS to downregulate the RIG-I antiviral response (Xia et al, 2015).