Pepsinogens are mainly grouped in 5 different groups based on their primary structure
1. Pepsinogen A (also called pepsinogen I)
2. Pepsinogen B
3. Progastricsin (also called pepsinogen II and pepsinogen C)
4. Prochymosin (also called prorennin)
5. Pepsinogen F (also called pregnancy-associated glycoprotein).
Kageyama T (February 2002). “Pepsinogens, progastricsins, and prochymosins: structure, function, evolution, and development”. Cellular and Molecular Life Sciences. 59 (2): 288–306. doi:10.1007/s00018-002-8423-9. PMID11915945. S2CID8907522.
