TNKS and colorectal cancer: In contrast, the recently described iron chelator, 21H7, which inhibits constitutive Wnt signalling and growth in colorectal cancer cells [39] independent of tankyrase or Axin stabilization (Fig. S1), blocked MDA-MB-231 (Fig. 6A), DLD-1 and SW480 (Fig. 6B and C) cell growth with IC50s in the range of 0.6–1.0 μM, as expected [39].