PTBP1 and hepatocellular carcinoma: confirm the mechanism of MTR4 participating in inducing the aerobic glycolysis phenotype of HCC cells: Ectopic expressed in HCC tissues and serum exosomes, MTR4 regulates coordinated alternative splicing by recruiting polypyrimidine tract binding protein 1 (PTBP1) to the intron region of target pre-mRNA.