glycoproteins, ribonucleate 3'-pyrimidino-oligonucleotidohydrolase) is a superfamily of pyrimidine-specific endonucleases found in high quantity in the pancreas of certain mammals and of some reptiles.

[2] The human genome contains 8 genes that share the structure and function with bovine pancreatic ribonuclease, with 5 additional pseudo-genes.

The sequence of pancreatic ribonucleases contains four conserved disulfide bonds and three amino acid residues involved in the catalytic activity.

[7] Human genes encoding proteins containing this domain include: Some members of the pancreatic ribonuclease family have cytotoxic effects.

[9] Two pancreatic ribonucleases isolated from the oocytes of the Northern leopard frog - amphinase and ranpirnase - are not inhibited by RI and show differential cytotoxicity against tumor cells.