In BC cells surviving after chemotherapy, chemotherapeutic agents, such as doxorubicin or paclitaxel, can activate the EZH2/STAT3 axis in BC cells, leading to the secretion of exosomes rich in miR-378a-3p and miR-378d, which can induce drug resistance by targeting DKK3 and activating the Wnt/β-catenin signaling pathway [83]. The gene discussed is STAT3; the disease is breast cancer.