ESR1 and neoplasm: It was observed that co-expression of CDK8 and leptin receptor (OBR) exacerbated the malignancy of the ER-negative breast cancer and significantly reduced the overall survival rate of the ER-negative patients who are associated with chemotherapy failure [89], suggesting that CDK8 may play a synergistic role in OBR signaling to promote tumor cell survival and maintain chemoresistance [89].