As a result of the attenuation of CBP/β-catenin mediated transcriptional activity, PRI-724 significantly reduced the expression of TCF/β-catenin dependent target genes related with cell proliferation such as CCND1, a cell cycle regulator well-known by its role in tumorigenesis [41,42], and CDC25A. The reduction of CDC25A expression at mRNA and protein level is of special clinical relevance, since CDC25A has been described as a major cell proliferation mediator in STS, both in vitro and in vivo [13]. This evidence concerns the gene CCND1 and telomere syndrome.