DYRK1A and trisomy 21: A recent review characterizes the main challenges of pharmacologically inhibiting DYRK1A and targeting trisomy as the bridging of two knowledge gaps: (1) the lack of understanding of the downstream targets of excessive DYRK1A activity leading to the typical phenotypic signs of trisomy 21; and (2) the bioavailability, specificity, and dose-dependent inhibition of DYRK1A by candidate inhibitors must be ascertained for specific tissues, and correlations between pharmacological actions and therapeutic outcomes need to be established [66].