p73 knock-out mouse embryos show an increase in the CBP/β-catenin interaction. Under control conditions, i.e., wild-type DMSO-treated (WT-DMSO) embryos (E13.5), relatively similar levels of β-catenin associated with CBP and p300 were observed. However, knock-out (KO) of p73 led to a dramatic increase in the proportion of β-catenin bound to CBP compared to p300 with DMSO treatment. CBP/β-catenin antagonist ICG-001 treatment normalized the aberrant coactivator distribution interaction nearly back to WT-DMSO levels. IP, immunoprecipitation. Ctl, control antibody. Detailed information can be found at Figure S2.