<p>by Johan Duchêne</p> Poorly validated antibodies generate misleading results and waste research resources. Two new studies in PLOS Biology quantify the ethical costs of this issue, examine why unvalidated antibodies are still used, and identify solutions to reduce their use. Poorly validated antibodies generate misleading results and waste research resources. This Primer explores two new studies in PLOS Biology that quantify the ethical costs of this issue, examine why unvalidated antibodies are still used, and identify solutions to reduce their use.