MAPK8 and cancer: Moreover, there have been conflicting reports on the role of the ROS-induced JNK pathway in cancer progression.34 It was reported that ROS accumulation is a key factor for tumour formation.35 However, ROS-induced JNK activation was also found to have an anti-cancer effect via inducing cell apoptosis.8,36 Herein, we demonstrated that the G6PD-suppression-induced activation of the JNK pathway impeded the EMT process and lymphatic metastasis of OSCC.