Figure 5.

Timeline of landmark patent approvals and rejections. The initial guidelines regarding patentable material were published in 1952. The guidelines were altered in 1980 to include non-naturally occurring man-made living organisms. In 1998, Newman–Rifkin applied for a general chimera patent and continued to apply until all reapplications were exhausted. A patent for organ regeneration using pluripotent cells was approved in Japan in 2015 and submitted for U.S. approval in 2021.