Unfortunately, preclinical research studies frequently suffer from a lack of rigor and robustness that precludes their use as a foundation for a drug-development program. Too often they lack the characteristics that typically are expected in high-quality clinical studies, yet despite that, they are published in top-tier scientific journals. The key attributes that are missing include lack of blinding of investigators, failure to repeat experiments, lack of positive and negative controls, use of nonvalidated reagents, inappropriate use of statistical tests, and data selection (ignoring results that do not fit the hypothesis). Physicians and scientists should view preclinical findings that lack these characteristics with skepticism and should proceed very cautiously in applying such findings to the clinic.