RRM2 and neoplasm: However, a hypergeometric distribution method found that RRM2 hub genes in HB and HCC tumors are similarly enriched in the pathways involved in cell proliferation and DNA repair (RRM2-associated pathways, or PTWAYRRM2) while RRM2B hub genes in both tumor types showed participation in stress and inflammatory response pathways (RRM2B-associated pathways, or PTWAYRRM2B) (Fig. 2e).