X-press Tag is an N-terminal leader peptide; this N-terminal peptide contains a polyhistidine sequence, the Xpress epitope (part of bacteriophage T7 gene 10 protein) and an enterokinase cleavage site. Anti-Xpress antibodies recognize the Xpress epitope sequence found in this leader peptide.

H-Ala-Asp-Ala-Gln-His-Ala-Thr-Pro-Pro-Lys-Lys-Lys-Arg-Lys-Val-Glu-Asp-Pro-Lys-Asp-Phe-OH

Selaginellin has a neuroprotective effect against L-glutamate-induced neurotoxicity through mechanisms related to anti-oxidation and anti-apoptosis via scavenging reactive oxygen species and up-regulating the expression of klotho gene.