The lab should just be open and in the list of locations after the scene that locks the outdoor mall.I'm stuck, I'm at Chapter 6 where the Outdoor Mall gets locked and I don't know what to do, I killed the bosses that revived multiple times and done side missions and got to every area and looked if I overlooked something but I can't find "The Doctor" or "The Lab" or what it was called, I read all the comments but couldn't find anything that would help me, does someone know how to progress?