The four-year-long battle for the CRISPR-Cas9 patent between Harvard University, the Massachusetts Institute of Technology (MIT) and University of California - Berkeley has finally ended. However, it seems that this is not the end of the issue.

TIME reported that three judges, who were from the Patent Trial and Appeal Board, have ruled that patents on the CRISPR-Cas9 gene-editing technology belong to the Broad Institute of Harvard University and MIT. It was first developed by UC Berkeley's Jennifer Doudna and Emmanuelle Charpentier, who was with the University of Vienna at the time.

UC Berkeley filed a patent in May 2012 for ownership of the technology. This includes ownership of its uses in all types of cells.

In Apr. 2014, the Broad Institute filed the same request. By then, the office had not ruled out the application yet. The institute's application, on the other hand, focused on eukaryotic cells, which include plant, animal and human cells.

Broad Institute paid for expedited review and received the patent. This led to UC Berkeley filing a suit against the institute last year, with claims that the patents with Broad "interfered" with their original request.

On Wednesday, the judges ruled that Broad Institute's technique was different from the technology of Berkeley. This led them to decide that it could be patented "independently and separately."

According to Quartz, Doudna and her research team described a simple gene-editing system for the precise cutting of DNA in a test tube in their paper which was published in 2012. In Jan. 2013, Broad Institute researcher Feng Zhang used the gene-editing technique within living cells.

The UC Berkeley research team argued that what Zhang did was only a refinement of their original work. The university believes that it should own the IP rights to the CRISPR technology because their research team was the one who invented the system.

MIT Technology Review noted that the "legal wrangling" for the technology will not be over any time soon. The judges only ruled one Berkeley claim on a single patent related to the CRISPR-Cas9. However, Broad has also filed several patents, which Berkeley can still challenge.