**SPOILER ALERT: READ ONLY IF YOU'VE BEATEN PORTAL 2**
I've been thinking a lot about the storyline to Portal 2 and it seems we have a family connection here and the more I think about it the more obvious it becomes. In short, Chell (who you play in the game) is the daughter of Cave Johnson and his assistant Caroline. You have all the references to "bring your daughter to work day," the potato project which was probably done by Chell (maybe explaining how she got there in the first place?), a very Chell looking Caroline seen in a portrait of Cave Johnson, and GLaDOS singing "She was a lot like you, maybe not quite as heavy, now little Caroline is in here too" suggesting Chell looks a lot like her mom Caroline (whose brain was transferred into the main computer, we learn via Cave's announcements). As we go along, GLaDOS becomes more in tune with the Caroline side of 'her' which helps Chell in the end as GLaDOS doesn't want to kill her, but wants her to just leave. The companion cube is a gift, maybe better than cake? So what do you think?