Just noticed ingame that even after regenerating mobs are hit with the cellrot ability, they still regenerate their health despite the Temporary Cellrot mechanic saying that the target cannot heal for 20 seconds. I'm not sure if healing is a different mechanic to regeneration or something, but this seems like a bug to me as the mobs do infact heal/regenerate life even after being hit with this skill. 

This may also apply to other weapons that have similar abilities which prevent healing, I haven't had a chance to test other weapons with Temporary Cellrot yet :)