Cross reference
Acts 20:8
8 There were many lights in the upper chamber where we{TR reads "they" instead of "we"} were gathered together.
Acts 1:13
13 When they had come in, they went up into the upper room, where they were staying; that is Peter, John, James, Andrew, Philip, Thomas, Bartholomew, Matthew, James the son of Alphaeus, Simon the Zealot, and Judas the son of James.
Luke 22:12
12 He will show you a large, furnished upper room. Make preparations there."