To study the impact of OTUB1 on breast cancer in vivo, we established the mouse allograft model by subcutaneously injecting control, OTUB1−/− and OTUB1−/− + CCN6 (OTUB1−/− cells transfected with CCN6‐overexpressing plasmids) 4T1 cells in nude mice. This evidence concerns the gene CCN6 and breast cancer.