OTUB1 and infection: In addition, Otub-1 expression was not evident early on, although it increased as the infection progressed, with a peak occurring at day 36 p.i. Finally, GRAIL expression was not observed at 42 days p.i. while Otub-1 protein expression was observed (Fig 4A), showing that GRAIL downregulation happened later on in the infection and depended on Otub-1 expression.