To investigate the cell viability of CSN6-knockdown melanoma cells, a 3-[4, -5-dimethylthiazol-2-yl]-2, -5-diphenyltetrazolium bromide (MTT) assay was conducted and revealed that CSN6 knockdown remarkably inhibited melanoma cell proliferation in vitro (Fig. 2B). Here, COPS6 is linked to melanoma.