Regulator System.

The regulator systems of Cosmos (promoters and repressors: see Section 4.3.3) have no equivalent in Tierra. They were designed specifically to allow cells in a multicellular organism to be able to influence which sections of code were being executed in neighbouring cells, thereby promoting cell differentiation and specialisation. The design of the regulator systems was inspired by the processes of chemical signalling between cells, and the use of promoter sequences and repressors within cells, in biological organisms.