For example, miR-520b suppressed tumour formation in breast cancer and hepatocellular carcinoma by targeting MAP3K2 and cyclin D1, miR17/20a inhibited tumour growth via targeting the MAP3K2-Erk5 pathway in vivo43, and miR-26a promoted glioblastoma cell growth in vitro via targeting MAP3K230. Here, MAP3K2 is linked to breast carcinoma.