Dual-luciferase reporter assays confirmed that Jab1 was a direct regulatory target of let-7d, whereas in vitro assays on MDA-MB-231 and MCF-7 cells and xenograft in vivo assays demonstrated a role for let-7d in regulating breast cancer cell proliferation, invasion and tumor growth in vivo [57]. Here, COPS5 is linked to breast carcinoma.