CTNNB1 and Down syndrome: By utilizing various tissue-specific Cre recombinase expression systems (Zechner et al. 2003; Pirone et al. 2017; Newman et al. 2018b), the effects of β-catenin alterations have been studied in a spatio-temporal manor, determining the important role of β-catenin in organ and body development, yet these mouse model lack specific CTNNB1 syndrome patient characteristics and are not suitable to use them as a mouse model to validate potential therapeutic solutions.