Lo is often called the father of noninvasive prenatal testing. After discovering fetal DNA in maternal blood, Lo catalyzed a medical revolution that has saved millions of pregnant people from having to undergo invasive tests like amniocentesis. With Lo’s pioneering technical advances, those who are pregnant can easily and reliably be screened for Rh factor mismatch, trisomies, and genetic disorders, and the implications of his work have and may go further in cancer testing, transplantation, and perhaps beyond.