CTNNB1 and Parkinson disease: Moreover, consistent with these DNA methylation changes, a significant reduction in the mRNA and protein levels were observed for four Wnt and neurogenesis-related genes, namely Forkhead box C1 (FOXC1), Neurogenin 2 (NEURG2), Sprouty RTK signalling antagonist 1 (SPRY1) and catenin beta 1 (CTNNB1), in the midbrain dopaminergic neurons of PD brains.