The notion that oncologists could boost immunotherapy responses simply by giving infusions in the morning, rather than late afternoon, is an attractive one. So when a clinical trial published in Nature Medicine this month showed that lung cancer patients treated in the morning had a massive reduction in the risk of progression compared to those treated in the afternoon, many scientists were intrigued, if skeptical.

Now that study is coming under fire, as multiple scientists and sleuths raise serious concerns about the data and point out inconsistencies in the trial.

These have called the study’s conclusions even further into question, which experts told STAT already lacked strong biological plausibility, and Nature Medicine appended a note on the study on Thursday that it is starting an investigation into the concerns.

Among the main concerns raised are inconsistencies in the trial design on its clinicaltrials.gov registration page, chronological errors in the submitted trial protocol, concerns related to the progression-free survival data, and oddities related to the side effect or adverse event data. Study authors declined to comment for this article, and told STAT in an email that they are first working on a response to Nature Medicine.