MCL1 and infection: The appearance of the PARP cleavage fragment in Bak-silenced Huh7 cells at 24 hours post-infection, albeit at lower levels as those in similarly infected Mcl-1 and EGFP knockdown Huh7 cells, could be attributed to a slight decrease in Mcl-1 expression in the Bak knockdown cells (Fig. 3B).