Before revision:  Further, subgraph prediction tasks present several unique challenges , because subgraphs can have non-trivial internal topology, but also carry a notion of position and external connectivity information relative to the underlying graph in which they exist.
After revision:  Further, subgraph prediction tasks present several unique challenges : subgraphs can have non-trivial internal topology, but also carry a notion of position and external connectivity information relative to the underlying graph in which they exist.