Repeated failures to replicate reported experimental results could indicate scientific misconduct or simply result from unintended error. Experiments performed by one individual involving tritiated thymidine, published in two papers in Radiation Research
, showed exponential killing of V79 Chinese hamster cells. Two other members of the same laboratory were unable to replicate the published results in 15 subsequent attempts to do so, finding, instead, at least 100-fold less killing and biphasic survival curves. These replication failures (which could have been anticipated based on earlier radiobiological literature) raise questions regarding the reliability of the two reports. Two unusual numerical patterns appear in the questioned individual’s data, but do not appear in control data sets from the two other laboratory members, even though the two key protocols followed by all three were identical or nearly so. This report emphasizes the importance of: (1) access to raw data that form the background of reports and grant applications; (2) knowledge of the literature in the field; and (3) the application of statistical methods to detect anomalous numerical behaviors in raw data. Furthermore, journals and granting agencies should require that authors report failures to reproduce their published results.