Example of subnetwork extraction for one artificial data set. The top left area shows the network of 31 nodes that have been sampled from the normal distribution with μ = 0 and σ = 5, thus being the regulated ones in the artificial data set containing 1000 nodes in total. The remaining three areas show networks reconstructed by the proposed algorithm using different values of the parameter α. The colouring represents the level of regulation, where down-regulated nodes are coloured blue, up-regulated ones red and non-regulated nodes white (the darker the colour the stronger the regulation). The differences between the original and the reconstructed subnetworks are highlighted by green ellipses.