Stem cell research has been exploding in the 21st century as a new medium to understand and manipulate the human body for therapy and development. In the field of regenerative medicine, there are a number of ethical limitations that prevent the onset of future research. In the past, there was a high focus on the use of embryonic stem cells. However, we are at a period of large scientific growth privately, which has caused a new set of developments in human-animal chimera. These technologies are designed specifically to assist in the large organ shortage issue, but can have major implications and unintended consequences due to the experimental nature of the work.