After the virus infection, knockdown or overexpression of UBC9 displayed differential SUMOylation status of BmTCTP. It was also shown that the decreased expression of BmTCTP following the virus challenge was partially rescued by overexpression of BmUBC9 rather than its knockdown, which implied that BmUBC9 may regulate BmTCTP expression as well. The gene discussed is UBE2I; the disease is viral infectious disease.