Rhetorical studies on experimental research articles in science have focused predominantly on introductions and discussions. The contextual nature of Results sections—the empirical heart of a scientific article—remains largely unexplored, however. What is known about the content of these sections comes from prescriptive style guides, which define Results as purely expository, leaving the argumentation to other sections of the article. This study examines one eminent biochemist's publications over time and a sampling of current articles authored by other biochemists. Six rhetorical moves were identified: (a) justifications for methodological selections, (b) interpretations of experimental results, (c) evaluative comments on experimental data, (d) statements citing agreement with preestablished studies, (e) statements disclosing experimental discrepancies, and (f) statements admitting interpretive perplexities. This investigation demonstrates that biochemists explicitly argue for the validity of their experimental data by employing certain rhetorical moves. Moreover, the findings challenge the traditional lore that Results sections engage in only simple, factual reporting.