C. perfringens is a ubiquitous gram-positive spore-forming bacterium found in human commensal gut flora and also includes specific strains frequently associated with enterotoxin-mediated food poisoning.42 We observed T-cell reactivity to ABC-TP p204–217 in peripheral blood of NMO patients, as well as cross-reactivity between it and AQP4 p63–76. This evidence concerns the gene AQP4 and neuromyelitis optica.