For example, STAT5A could promote the proliferation and metastasis of breast cancer cells by mediating NOX5-L expression.[18] Another study revealed that STAT5B could inhibit tumor cell invasive characteristics of BRCA.[19] Jak2/STAT5B pathway was associated with inhibiting tumor growth and metastasis in ER-positive breast cancer.[20]. This evidence concerns the gene JAK2 and breast carcinoma.