For instance, one of the most highly inducible ISGs, ISG15 ubiquitin like modifier (IFN-stimulated gene of 15 kDa; ISG15), is expressed by cardiomyocytes in response to the type I IFN IFN-β, and it is induced in cardiomyocytes in response to viral infection (15, 16). Here, ISG15 is linked to viral infectious disease.