STING1 and viral infectious disease: Consistent with these observations, the basal ubiquitination of STING, interaction between TBK1 and STING, and the expression of several downstream genes were increased in USP13-knockdown THP-1 cells or in USP13 deficient cells compared to the controls without viral infection, indicating that USP13 keeps the innate immune signalling in check in unstimulated cells.