(A) TOP flash and FOP flash relative luciferase active tests were used to detect the activity of the Wnt signalling with RTL1 overexpression or knockdown. Compared to FUGW, * p<0.05. Compared to Tet-on shRTL1-1 without DOX, # p<0.05; (B) the expression of β-Catenin stablizing genes in A375 cells with RTL1 overexpression or knockdown, * p<0.05; (C) β-Catenin expression in A375 cells with RTL1 overexpression or knockdown was detected by western blot; the protein level was analyzed by Densitometry, compared with the control group (FUGW and Tet-on shRNA without DOX), * p<0.05. (D) Analysis of the immunohistochemical expression levels of β-Catenin in human melanoma and nevus tissues, three tissues were examined; (E) CCK8 assay detecting the cell proliferation of A375 cells with RTL1 overexpression and with treatment with the WNT inhibitor FH535. Compared to FUGW, * p<0.05 and ** p<0.01. Compared to RTL1-overexpressing cells, # p<0.05; (F) cell cycle of A375 cells with RTL1 overexpression and with treatment with the WNT inhibitor FH535 was detected by FACS. Compared to FUGW, * p<0.05 and ** p<0.01. Compared to RTL1-overexpressing cells, # p<0.05 and ## p<0.01.