C4A and hepatocellular carcinoma: In this study, expressions of serum and exosomal LDHC mRNAs in stages I-II HCC were explored using qRT-PCR, and levels of LDH-C4 in HCC tissues were quantitated by high-throughput tissue microarray and IHC analyses, and correlations between LDH-C4 expression and clinical pathological characteristics and between the expression and the prognosis of HCC patients were analyzed.