STAT3 and hepatocellular carcinoma: Highly expressed circMALAT1 reduces the inhibitory effect of miR-6887-3p on JAK2 through molecular sponge action, thereby upregulating the expression levels of JAK2 and enhancing its phosphorylation, then activating the JAK2/STAT3 signaling pathway to promote the self-renewal of HCC CSCs; meanwhile, circMALAT1 can also combine with ribosomal and paired box 5 (PAX5) mRNA coding sequences to form a specific ternary complex (ribosome-circRNA-mRNA) to exert mRNA braking.