Injecting human stem cells into animal embryos will no longer make researchers ineligible for National Institutes of Health Funding, the agency announced August 4.

According to the New York Times, this change in stem cell research is different from research injecting regular human cells into animals. Human stem cells can then develop into any type of cell, and mixing human and animal stem cells, able to fuse or grow in any manner the researchers choose, can conjure up uncomfortable images of human-other animal hybrids. For example, if a human stem cells then develops into a human brain cell inside of another animal, what does that mean?

On the other hand, the insights gained from such research could help physicians better understand tumors and make organ transplant discoveries. Those advances could make it useful and productive for the NIH to invest in such funding.

Check out the New York Times to see more about the logistics of lifting the ban, plus more arguments for and against the move.