DYRK1A is a member of the dual-specificity tyrosine phosphorylation-regulated kinase (DYRK) family and is thought to be involved in neuronal differentiation, neurodegenerative diseases, and is considered to be a strong candidate gene for learning defects associated with Down syndrome. DYRK1A phosphorylates several transcription factors such as p53, leading to inhibition of embryonic neuronal cell proliferation. DYRK1A associates with multiple proteins, including SPRED1 and SPRED2; this association appears to inhibit the phosphorylation activity of DYRK1A. Recent evidence also suggests that DYRK1A may be involved in the replication of HIV-1.