An increase in VEID cleavage over time was observed for both C6wt and C6ko cell lines (Fig. 2F ). For C6wt cells, significant increases over baseline were observed at all time points, whereas the C6ko cells show lower VEID processing initially with a nonsignificant increase in the first 2 h of treatment. However, at later timepoints C6ko cells exhibit similar levels of VEID cleavage as C6wt with a highly significant increase over non-treated controls (Fig. 2F) , suggesting that other proteases make up for a large proportion of the VEID cleavage activity in apoptotic extracts. These results indicate that the lamin protein substrates are much more specific for cleavage by caspase-6 than the VEID peptide.