Before revision:  More remarkably, besides the silenced and transcriptionally active fate of chromatin, our model leads to a novel state with bivalent  marks under certain perturbations (knock-out mutations, inhibition or enhancement of enzymatic activity).
After revision:  More remarkably, besides the silenced and transcriptionally active fate of chromatin, our model leads to a novel state with bivalent (i.e., both active and silencing) marks under certain perturbations (knock-out mutations, inhibition or enhancement of enzymatic activity).