SPHK1 had shortest paths of 2 across MMP-2, MMP-9, and ABCG2, whereas shortest path of 1 with ABCC1. Similarly, CERK also had shortest path length of 2 across MMP-2, MMP-9, ABCG2, and ABCC1. CERK was functionally close with other candidates, indicating it to be playing major role in maintaining the regulatory interactions during breast cancer. This evidence concerns the gene ABCG2 and breast cancer.