HMCLs display constitutive Wnts signaling. (A) Percentage of transduced cells in HMCLs transduced with empty vector control or dnTCF4 expressed from bicistronic lentiviral vectors, relative to day 0. The mean ± standard deviation (SD) of 3 independent experiments in triplicate is shown. *P ≤ .05, **P ≤ .01, ***P ≤ .001 using unpaired Student t test. (B) Flow cytometry analysis of the effect of small-molecule Wnt secretion inhibitor IWP-2 (2.5 µM) and LGK974 (2.5 µM) on HMCL cell expansion in a 4-day time course, relative to day 0. The mean ± SD of 3 independent experiments in triplicate is shown. **P ≤ .01 using unpaired Student t test. (C) Flow cytometry analysis of the effect of small-molecule Wnt secretion inhibitor IWP-2 (2.5 µM) and LGK974 (2.5 µM) on the expansion of HMCL LP1 transduced with S33Y mutant β-catenin or the empty vector control in a 4-day time course, relative to day 0. The mean ± SD of 3 independent experiments in triplicate is shown. Not significant (ns) P > .05, **P ≤ .01 using 1-way analysis of variance with Bonferroni correction.