USP15 and hepatocellular carcinoma: MeRIP-qPCR experiments showed that m6A enrichment of USP15 in HCC cells decreased after the knockdown of Mettl3, while Mettl3 overexpression significantly increased the m6A enrichment of USP15. In an actinomycin D experiment, knockdown of Mettl3 reduced USP15 stability, while overexpressing Mettl3 increased USP15 stability (Fig. 8G–I).