In conclusion, our findings illustrated that circMAPK1 promoted KDM2B mRNA decay via recruiting UPF1, thereby inhibiting KDM2B-mediated WNK1 demethylation to suppress WNK1 expression, and ultimately triggering NLRP3-mediated pyroptosis to exacerbate sepsis-induced lung injury (Fig. S2). Here, UPF1 is linked to Sepsis.