When we "control" computers from outside, there is nothing observable from within the computer that can denote the control.
In exactly same way, the control is happening from outside cells to make them achieve an objective, which also is set from outside. DNA are only like subroutines to create stuff in localised environment, but not orchestrators of how the overall system is evolving.
Thie type of source of control is in form of information, and that information flow must be top-down, without any cellular or other boundaries.