The expansion is performed using the PC-IM algorithm. The algorithm receives a gene network and a set of new genes, and tries to find relationships between them by exploiting the PC algorithm. PC-IM is an iterative implementation of the PC algorithm, which finds a gene network and studies its causal relationships, aimed to estimate if a list of new genes can have a causal relationship with an already known GRN. In particular, the new genes are partitioned in blocks and merged with the GRN. Afterwards the PC is applied on each block to look for new possible relationships. At the end of the process the algorithm self-evaluates its performance, and based on this, decides the final network to return as an output.