GPC3 and hepatocellular carcinoma: Leveraging immuno‐PCR, with unique molecular tags specifically bound to protein markers of HCC CTCs (EpCAM‐oligo1, GPC3‐oligo2, and ASGPR‐oligo3), well‐preserved mRNA markers and quantified protein oligos were obtained from the MRX‐CTC chip (Figure S1, Supporting Information), which was ultimately integrated with our cross‐dimensional MRT‐dPCR to achieve simultaneous and accurate absolute quantification of transcriptotypes and phenotypes (Figure 1a).