SP1 and melanoma: Mechanistically, JP1 targets and enters melanoma cells with high expression of integrin αvβ3 through RGD, then interacts with MEK1/2 and further activates the E3 ubiquitinase NEDD4L (neural precursor cell expressed developmentally downregulated 4-like), accelerates the degradation of SP1 via its K685, and finally exerts a transcriptional inhibitory effect on integrin αvβ3 in targeted A375 cells [26].