The general evaluation of β-catenin-dependent transcriptional activity by luciferase reporter gene expression (TopFlash/FopFlash plasmids) showed significant differences only in the case of melanoma 29, whereas cell populations isolated from patient 8 and patient 35 displayed minimal differences (data not shown), indicating that the activity of synthetic multimerized LEF/TCF binding site upstream to the Thymidine Kinase (TK) minimal promoter may discriminate only marked differences in β-catenin protein abundance. The gene discussed is TKT; the disease is melanoma.