CD47 and melanoma: The role of NRF-1 in the expression of CD47 was confirmed by siRNA knockdown of NRF-1 in vemurafenib-resistant melanoma cells generated in vitro and in vivo, which showed that knockdown of NRF-1 reduced the expression levels of CD47 in Mel-CV.S cells and cells from a post-treatment primary culture with increased CD47 (Figure 5F and 5G).