Add the ability to have +1 interactomes limited to a list of genes

[Giorgio Favrin]

This network should have the + 1 interactions of a list of genes, BUT it should show only a +1 gene (i.e. not in the original list) if it is an interactor of at least two genes in the original list.

Or in other words - from the whole +1 interactome- remove the +1 interactions to only one gene of the original list.