PLGA-encapsulated Levosimendan not only alleviates repeated low-dose CDDP-induced renal fibrosis, but also significantly enhances the chemotherapeutic effects of cisplatin in several xenograft and syngeneic mouse tumor models by suppressing the Mettl3/Pfkfb3/lactate/ H3K18la/PD-L1 axis. This evidence concerns the gene METTL3 and renal fibrosis.