Occupancy bias correlation between the full system and the subsystems. We consider the smallest subsequence (46 Kbp) and the corresponding regions in all other sequences and we computed the Pearson correlation coefficient between occupancy biases. First, we compute the average occupancy bias for the full system using 60 independent simulations and then, for each simulation (including the full system), we compute the correlation of the current occupancy bias and the mean value of the full system. Only lacI molecules were added to the system and each simulation was run for: 2000 s (in the case of 10 molecules), 200 s (in the case of 100 molecules) and 20 s (in the case of 1000 molecules). On the first row none of the parameters are changed, while on the second and third ones, the number of lacI molecules and the association rate was varied according to the system size.