CCND1 and melanoma: The differential expression of Wnt/β-catenin pathway components and target genes in melanospheres (e.g., the gene encoding multi-potent MITF) versus monolayers (e.g., the genes encoding CTGF, which is involved in invasiveness, and cyclin D1, which promotes proliferation) suggests that the microenvironment has a strong influence on the functional outcome of the Wnt/β-catenin pathway in melanoma.