Comment on "Study on the association between Mettl3-modified Piezo1 in CD4+ T cells and inflammatory response in ankylosing spondylitis".

We read with interest the recent article by Ren et al. on METTL3-mediated m6A modification of Piezo1 in CD4+ T cells and inflammatory responses in ankylosing spondylitis (AS). The findings are intriguing, but several aspects limit the strength of the proposed pathogenic and diagnostic interpretation. The study relied on peripheral blood CD4+ T cells, whereas AS pathobiology is shaped by tissue-proximal immune responses at the enthesis and, importantly, within the synovial compartment. Bulk CD4+ T-cell analysis also overlooks the marked heterogeneity of both CD4+ and CD8+ T-cell states now recognized in spondyloarthritis. In addition, m6A enrichment on Piezo1 transcripts does not by itself establish direct METTL3-dependent regulation without higher-resolution mapping and functional rescue experiments. Finally, the reported high diagnostic performance of peripheral Piezo1 should be interpreted cautiously because strong discrimination may reflect systemic inflammation or shifts in circulating immune-cell composition rather than an AS-specific mechanism. Overall, the work is hypothesis-generating, but tissue-relevant validation and more rigorous mechanistic studies are needed before the METTL3-Piezo1 axis can be considered a defined pathogenic or biomarker pathway in AS.