The infection with CyHV-3 increased the transcript levels of apoptosis-related genes in the skin of non-vaccinated carp, hallmarked by a two- to 13-fold upregulation of apaf1, casp9 and iap at 2 dpc and p53 at 7 dpc (Supplementary Figures 5A, C,–E). Here, APAF1 is linked to infection.