Reply to: Absence of evidence that Slc12a8 encodes a nicotinamide mononucleotide transporter

Grozio A, Mills K, Yoshino J, Bruzzone S, Sociali G, Tokizane K · Nature Metabolism

The original authors' response, defending the transporter assignment and addressing the reanalysis point by point. The exchange ended without resolution, and how oral NMN enters human cells remains an open question.

Limitations

Correspondence; no independent group has since settled the question in human tissue.