GPC3 and hepatocellular carcinoma: This discrepancy highlights the dynamic nature of tumor progression, where the complex regulatory network of internal and external factors modulate HCC CTC biomarkers in vivo, including transcription factors, posttranslational controls, epigenetic modifications, and noncoding RNA‐mediated regulation.[19] Notably, we observed a significant difference in protein level variations between EpCAM and GPC‐3, despite similar mRNA variations.