Flowchart of the MAST approach. The Figure outlines the steps of the MAST procedure. In step 1, the MAST procedure finds MTOM neighborhoods around initial seed nodes. The software allows the user to specify an initial set of seed nodes or, as alternative, we have also implemented an automatic procedure for picking seed nodes. In step 2 the hub neighborhoods are extended to preliminary modules. In this step, the initial hub neighborhoods comprised of 20 nodes are grown into larger modules in a stepwise fashion. The module growth is subject to stopping rules. In step 3, preliminary modules may be merged. Since some of the preliminary modules may be very similar, it can be advantageous to merge them into larger modules. The merging step is repeated until no pair of modules can be found with a relative between-module similarity larger than the threshold.