Breaking: Nature has issued an Expression of Concern regarding a 1999 paper. The article, titled "En passant neurotrophic action of an intermediate axonal target in the developing mammalian CNS," faces scrutiny. Concerns arose over image irregularities in Figure 5.

The editors flagged unexpectedly similar background regions in panels 5a and 5b. These panels purportedly depict the same tissue explant at 24 and 52 hours. Authors stated the original data is unavailable due to the article's age. The paper was published online October 21, 1999.

Nature advises readers to interpret the paper's results cautiously. The core issue involves potential manipulation or errors in image presentation. This could impact the validity of the study's conclusions.

The paper explores how developing nerve cells are guided to their targets. It investigates the role of intermediate targets in the mammalian central nervous system. Such research is crucial for understanding neural development and potential therapies.

Further investigation is unlikely given the data constraints. The Expression of Concern serves as a permanent warning. Scientists should consider this when referencing the paper in future research.