The experimental results showed that the volume and weight of A375 and MV3 cells in the subcutaneous tumourigenesis of nude mice were significantly higher by circFCHO2 overexpression than those of the control group (Fig. 3A), and the positive rate of Ki-67, a cell proliferation marker, in the subcutaneous melanoma of nude mice in the circFCHO2 overexpression group was significantly higher than that of the control group (Fig. 3B). Here, MKI67 is linked to melanoma.