IGHG1 and breast cancer: Regardless of node status, highly co-expressed genes within the network of no recurrence were IGHA1, IGHD, IGHG1, IGHG3, IGLC2, and IGLJ3. Cox proportional hazard ratio regression analysis found these genes to be significantly correlated with the recurrence of BC, regardless of node status (Table 3, Fig. 1).