Immunofluorescence and semi-quantitative analysis of Ddit3 and Sod1 positive cells did show activation of ER stress and oxidative stress after Paxlovid treatment (Fig. 7G–J). A schematic chart was provided to illustrate the effect of Paxlovid on osteoarthritis and its mechanisms behind (Fig. 8). Here, DDIT3 is linked to osteoarthritis.