Companies in this industry hope that proteins made from plants can be used to develop treatments for some of the most serious diseases and conditions such as cancer, diabetes, HIV, heart disease, Alzheimer's disease, cystic fibrosis, multiple sclerosis, Hepatitis C, and arthritis, but no such products have as yet been approved. Conventional production methods for pharmaceutical proteins involve substantial investments of both time and finances. Not only are there manufacturing challenges involved with conventional production methods, but there are also considerable regulatory challenges that must be met. There are currently about 30 protein-based medicines on the market, and close to 100 in late-stage human trials. Consequently, companies are motivated to provide a wider range of options for production of proteins used in these treatments. Controversy over pharming Bioreactors for producing proteins, NRC Biotechnology Research Institute, Montreal, Canada The first such drug manufactured from the milk of a mammal, such as a cow, sheep, or goat, is a common application, as milk production is plentiful and purification from milk is relatively easy. Hamsters and Rabbits have also been used in preliminary studies because of their faster breeding. There is much debate over the practicality of using plants to produce proteins. Some groups fear that contamination of conventional crops might occur; in several instances, companies have been fined for violating protocols, resulting in potential contamination. This leads to the question of "Why would biotechnology companies use plants to produce proteins. Some groups fear that contamination.