PSMB9 and infection: Within this pathway, NFE2L2, which encodes a proteasome-regulated transcriptional factor involved in antioxidant genes, was downregulated, while the genes encoding the proteasome components PSMB2, PSMB3, PSMA2, PSMD2, PSMD8, PSMB6 and PSMB9 were upregulated in Mb04-303 infections.