Investigation shows journal editors getting paid to publish bunk papers, and new techniques for finding tumor DNA in the blood   First up on this week’s episode, Frederik Joelving, an editor and reporter for the site Retraction Watch, talks with host Sarah Crespi about paper mills—organizations that sell authorship on research papers—that appear to be bribing journal editors to publish bogus articles. They talk about the drivers behind this activity and what publishers can do to stop it.   Next, producer Zakiya Whatley of the Dope Labs podcast talks with researcher Carmen Martin-Alonso, a graduate student in the Harvard–Massachusetts Institute of Technology Program in Health Sciences and Technology, about improving liquid biopsies for cancer. They discuss novel ways to detect tumor DNA circulating in the blood.   This week’s episode was produced with help from Podigy.   About the Science Podcast   Authors: Sarah Crespi; Zakiya Whatley; Richard Stone    Episode page: https://www.science.org/doi/10.1126/science.zahpt8h   About the Science Podcast: https://www.science.org/content/page/about-science-podcast