Somatrem and somatropin are trade names for synthetic versions of human growth hormone (Protropin) that are made by bacteria using recombinant DNA techniques. Protropin stimulates skeletal growth in those patients that have a growth hormone deficiency. It is also used for long term treatment of children who have growth failure due to a lack of adequate endogenous growth hormone secretion. Unusual side effects include leukemia, although it has not been firmly established that the blood disease originated from treatment with human growth hormone.