In nonclinical in vitro studies a relationship dataset, Related References Dataset or relref.xpt, is used to identify how information is related to the design of the study and to other sources of information in the study. In genetic toxicology studies, the source of information may be from a variety of levels of the experiment. For example, information can be expressed on an entire assay, on replicate sets of petri plates from the same trial set (having the same test conditions) or on individual petri plates.
The relref.xpt dataset is used to show each source of information (each given a REFID), how it is related to the study design (STUDYID, GNTXAID, SETCD), and how it relates to other sources of information on the assay (PARENT, LEVEL, LVLDESC).