They secrete hormones, like rennin and erythropoietin, into the blood to regulate blood pressure and red cell production.
From the sciencedaily.com
Chymosin or rennin is an enzyme found in rennet.
From the en.wikipedia.org
Due to this reaction, rennin is used to bring about the extensive precipitation and curd formation in cheese making.
From the en.wikipedia.org
The epithelium and lamina are filled with connective tissue and covered in gastric glands that may be simple or branched tubular, and secrete mucus, hydrochloric acid, pepsinogen and rennin.
From the en.wikipedia.org
More examples
An enzyme that occurs in gastric juice; causes milk to coagulate
Chymosin or rennin is an aspartic acid protease enzyme found in rennet. It is produced by cows in the lining of the abomasum (the fourth and final, chamber of the stomach). ...
An enzyme secreted by cells lining the stomach in mammals, and that is responsible for clotting milk.
An enzyme used in coagulating cheese; is obtained from milk-fed calves