None of the Marbles Family been there in the lab except Marble since she's the only oc who has the demon part and animal parts that most people made fun of and bullied her.

And she's the only person to escape and moved to another place to avoid Crown Keychain looking for her even she found the location.

The reason why she came back to her old home because she'll free the others one day to avoid the others staying the same fate of getting experimented but the securities are improved including the door.