A system and method for rotating a cell growth chamber of a cell expansion system includes a rotatable member for engaging a chamber coupling attached to the cell growth chamber. The rotatable member includes an independently operable mechanism for engaging a rotatable fitting associated with the chamber coupling. In at least one embodiment, the chamber coupling is selectively rotatable by turning the rotatable member, thereby rotating the cell growth chamber around a first axis. The cell growth chamber is also selectively rotatable around a second axis by turning the rotatable fitting associated with the chamber coupling. Other novel aspects include a way of attaching the cell growth chamber to the shaft assembly, and a new tube routing clip.