Activation of canonical WNT signaling by the WNT3a ligand or inhibitor of GSK-3β kinase induced apoptosis in melanoma and neuroblastoma cell lines due to the upregulation of the expression of pro-apoptotic gene BCL2L11 in melanoma, and the downregulation of cyclin D1 in neuroblastoma [18,19,20]. Here, CCND1 is linked to neuroblastoma.