Genetic alternations resulting in constitutive stabilization of β-catenin and altered transcription of β-catenin/TCF-regulated genes are found in many cancers. A recent Nature paper offers insights into the role of tankyrase in regulating the Wnt/β-catenin pathway and suggests that compounds targeting tankyrase''s poly-ADP-ribosylation (PARsylation) activity may hold promise for cancer therapy. [Copyright &y& Elsevier]