GRP20–29, frog is a 10-amino acid antigen peptide that can be isolated from Xenopus[1].
References
[1] Hirooka A, et al. The gastrin-releasing peptide/bombesin system revisited by a reverse-evolutionary study considering Xenopus. Sci Rep. 2021 Jun 25;11(1):13315. DOI:10.1038/s41598-021-92528-x