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. Two of its authors declare they are inventors on a patent over the Slc12a8 NMN transporter, applied for by Washington University and licensed to Teijin — so both sides of the exchange carry a declared commercial interest, pointing opposite ways.