IFIH1 and viral infectious disease: Unlike studies describing melanoma differentiation-associated protein 5 (MDA-5) and FBP2 cleavage upon picornavirus infection [41, 53], we showed that FBP1 cleavage was not processed by cellular mechanisms induced by viral infection, as treatment with proteasome inhibitor MG132 or the pan-caspase inhibitor QVD-OPh both failed to abolish cleavage, indicating that FBP1 cleavage is both a proteasome- and caspase-independent event (Fig 2).