"[M]assive peer-review fraud" prompted "disciplinary action" from the Chinese government against "more than 400 researchers listed as authors on some 100 now-retracted papers." In "an all-too-common scam," the "Chinese authors suggested 'experts'" to a Springer journal, Tumor Biology, that allowed authors to propose reviewers. The authors "provided email addresses that routed messages from the journal back to the researchers themselves, or to accomplices—sometimes third-party firms hired by the authors—who wrote glowing reviews ... ."
"Overall, 80 of the papers reported actual research results, investigators found. But nine were fraudulent, and 12 of the papers had been purchased outright from third parties by the supposed authors. The remaining six papers have various other problems or are still under investigation."
The journal itself does not garner much praise. "Tumor Biology, which is owned by the International Society of Oncology and BioMarkers, has a history of problems. In 2016 it retracted 25 papers all at once for similar peer-review problems. ... An investigation by ScienceInsider found that several scientists listed on its editorial board had no relationship with the journal and one had even passed away several years ago."
"SAGE took over responsibility for publishing the journal 'with the agreement that there would be a complete overhaul of the editorial structure and peer review practices of the journal, specifically the use of preferred reviewers,' a SAGE spokesperson wrote in an email to ScienceInsider.
Dennis Normile, China Cracks Down After Investigation Finds Massive Peer-review Fraud, Science, Jul. 31, 2017 , 2:30 PM; Dennis Normile, China crack down on Fraud, 357 Science 435 ( 2017) DOI: 10.1126/science.357.6350.435