To further confirm whether CRAF or MEK1/2 was required for anti-proliferation effect of erianin, CRAF or MEK1/2 was knocked down in A375 and SK-MEL-2, then the mutant CRAF or MEK1/2 was transfected into cancer cell and rescue assay was performed (Fig. 4d–h). Here, MAP2K1 is linked to cancer.