“…Fetal DNA is released into maternal blood, allowing Y chromosome detection in pregnancies with a male fetus. cfDNA can also be used for non-invasive prenatal Down syndrome screening ( Vrachnis et al, 2014 ; Malmir et al, 2021 ) and immune rejection surveillance after organ transplantation ( Snyder et al, 2016 ; Danovitch et al, 2021 ). The third source is the release of auto-activated DNA, cfDNA content is related to trauma, burn, infection, heart failure, stroke, and organ IRI level ( Tian et al, 2019 ; Dinsdale et al, 2020 ; Yokokawa et al, 2020 ; Zuo et al, 2020 ; Saravanan et al, 2021 ).…”