Using RT-qPCR of GAPDH gene, we have observed median cfDNA concentration of 16.88 ng/ml (IQR: 1.66–62.59 ng/ml) for healthy control, 33 ng/ml (IQR: 0.21–105 ng/ml) for CLD and 244 ng/ml (IQR: 179–287 ng/ml) for HCC patients. Here, GAPDH is linked to congenital secretory chloride diarrhea 1.