Interestingly, although Ad‐Hif‐2α infection promoted exogenous Hif‐2α expression, we could detect slightly decreased Hif‐2α expression by CJM and apigenin treatment in Figures 3B and 4D. The stability of Hif‐2α is controlled by expression of Hsp90 and proteasomal degradation mediated by E3 ubiquitin ligase.41, 42 Notably, apigenin manipulates the ubiquitin‐proteasome system and reduces the expression of Hsp90 in chondrocytes.43, 44 Apigenin may regulate protein stabilization of endogenous and exogenous Hif‐2α by regulation of the ubiquitin‐proteasome degradation system and Hsp90 expression. This evidence concerns the gene EPAS1 and infection.