It showed that 68% and 60% of serum and exosomal LDHC-positive cases, respectively, were reported in HCC; patients with high LDH-C4 expression in HCC tissues accounted for 55.84%. LDHC/LDH-C4 could be used as a useful biomarker for early diagnosis, efficacy evaluation, relapse monitoring, and prognosis prediction for HCC. This evidence concerns the gene C4A and hepatocellular carcinoma.