MAP3K3 and prion disease: Although pathway analysis of miRNA targets remains heavily biased towards non-neuronal pathways, the most significant pathway was ‘Prion Disease’ and included gene targets previously described for their involvement in addiction such as Bax (BCL2 associated X, apoptosis regulator), Egr1 (early growth response 1), Elk1 (ETS transcription factor ELK1), Mapk3 (Erk1) (mitogen-activated protein kinase 3) and Ncam1 (Neural Cell Adhesion Molecule 1) [4,39,40,41,42,43,44,45,46,47,48].