PRNP and prion disease: In prion disease miRNA-146a and other NF-kB-up-regulated, inducible miRNAs have been found to target the expression of genes involved in intracellular protein-degradation pathways and signaling pathways related to cell death, synapse function and neurogenesis as well as brain genes modulating microglial function by regulating their activation state during PrP-induced neurodegeneration (39–42).