(D) A model of Wnt signaling regulation by MDMX. In the absence of stress, MDMX inhibits CK1α, increases basal expression of Wnt/β-catenin target genes and stimulates proliferation. Interaction with mutant p53 stimulates MDMX-CK1α binding and promotes proliferation. DNA damage promotes MDMX degradation and inhibits MDMX-CK1α binding, reducing Wnt signaling. 