N-{(2S)-1-({(2S)-1-[(2,4-difluorobenzyl)amino]-1-oxopropan-2-yl}amino)-4-[(2S)-2-methylpiperidin-1-yl]-1,4-dioxobutan-2-yl}-5-methyl-1,2-oxazole-3-carboxamide (non-preferred name)

P9WHT9 — Proteasome subunit beta