Yoshiki Sasai

was a Japanese biologist. He was Director of the Laboratory for Organogenesis and Neurogenesis at the research institute RIKEN. Sasai was best known for developing new methods to grow stem cells into organ-like structures.
In 2012, Sasai became the first stem cell researcher to grow an optic cup from human cells.
On August 5, 2014, he was found dead hanging at the RIKEN institute in Kobe, Hyōgo. It is believed that he committed suicide.