In ICC, METTL3-induced m6A methylation of circSLCO1B3 stabilized its expression, which impaired antitumor immunity by suppressing the ubiquitin–proteasome-dependent degradation of PD-L1 by the E3 ubiquitin ligase speckle type BTB/POZ protein (SPOP) [120]. The gene discussed is CD274; the disease is intrahepatic cholangiocarcinoma.