Tumor　necrosis　factor-alpha　(TNF-alpha)-induced　protein　8-like-2　(TNFAIP8L2　or　TIPE2),　a　member　of　the　tumor　necrosis　TNFAIP8　family,　was　found　to　be　involved　in　the　development　and　progression　of　several　tumors.　However,　to　date,　the　role　of　TIPE2　in　breast　cancer　is　still　unclear.　Thus,　the　aim　of　this　study　is　to　explore　the　role　of　TIPE2　in　breast　cancer.　Our　results　indicated　that　TIPE2　expression　was　significantly　decreased　in　human　breast　cancer　tissue　and　cell　lines.　Overexpression　of　TIPE2　inhibited　the　proliferation　in　vitro　and　tumor　xenograft　growth　in　vivo.　TIPE2　also　inhibited　the　migration/invasion　of　breast　cancer　cells　through　preventing　the　epithelial-to-mesenchymal　transition　(EMT)　phenotype.　Mechanically,　TIPE2　inhibited　the　expression　of　beta-catenin,　cyclin　D1,　and　c-Myc　in　breast　cancer　cells.　In　conclusion,　our　findings　show　that　TIPE2　may　play　an　important　role　in　breast　cancer　cell　proliferation,　invasion,　and　tumorigenesis　in　vivo.　Therefore,　TIPE2　may　be　a　potential　molecular　target　for　the　treatment　of　breast　cancer.