Steadfast Progress in Stem Cell Research: Reflections and Resolve at the Start of 2026
As we pass the first month of 2026, stem cell research has already experienced both encouraging developments and serious challenges. In the United States, recent signals of a more restrictive stance toward research involving fetal tissue and human embryonic stem cells—particularly in the context of NIH policy—have been a source of deep concern for our field. The ISSCR has issued a formal statement addressing the fetal tissue policy change, and we sincerely hope that continued dialogue and advocacy will help improve the circumstances. Further the ISSCR will respond to the Request for Information (RFI) on Human Embryonic Stem Cells in NIH-Supported Research, continuing our longstanding defense of the stem cell field. For members who wish to share examples of the impact of limitations on hESC research with the media or policymakers, please let us know. These moments remind us that progress in stem cell science is never guaranteed and must be continually defended through evidence, transparency, and ethical responsibility.
At the same time, I would like to share several highly inspiring developments from Japan, where I currently reside. On January 22, the Yoshiki Sasai Memorial Symposium was held in Osaka, honoring the enduring legacy of Yoshiki Sasai. Professor Sasai’s contributions—from his foundational work on neural induction in Xenopus, to the discovery that inhibition of BMP signaling directs early embryos toward neural fate, and ultimately to his elucidation of intrinsic self-organizing principles in neural development—transformed our understanding of developmental biology. His pioneering establishment of three-dimensional culture systems capable of generating cerebral cortex and retinal tissues from ES and iPS cells laid the groundwork for brain organoid research, disease modeling, and regenerative medicine. Although 12 years have passed since his untimely death, his scientific influence remains as powerful as ever.
The symposium brought together many of Professor Sasai’s former trainees and close collaborators, including Juergen Knoblich, Juan Carlos Belmonte, Sergiu Pașca, as well as Jun Takahashi and Masayo Takahashi, who were both collaborators and university classmates of Professor Sasai. Together, we reflected not only on the remarkable path he forged, but also engaged in thoughtful discussion on what directions he might be pursuing if he were with us today. The depth and openness of these conversations made the symposium truly meaningful.
In addition, from January 26 to 29, a Keystone Symposium celebrating the 20th anniversary of induced pluripotent stem cells was held in Kyoto, organized by Shinya Yamanaka and colleagues. In his opening address, Professor Yamanaka compellingly traced the journey leading to the discovery of iPS cells, emphasizing both its transformative impact and the leadership required to bring this vision to reality, while also candidly addressing the challenges that remain. Over the course of the meeting, many researchers—including myself—presented on the remarkable evolution of iPS cell technology over the past two decades, spanning clinical applications, drug discovery, and emerging future directions. Beyond the scientific exchange, what left a particularly strong impression was the shared sense of purpose—a reaffirmation that we are united as colleagues and partners, working toward common goals for humanity. I cannot help but look forward to the ISSCR’s Symposium: 20 Years of iPSC Discovery: A Celebration and Vision for the Future that will be held in October in Kyoto, Japan. I know it will be an inspirational opportunity to connect the past with exciting prospects for the future of iPSC technology.
Taken together, these experiences remind us that our field will always face moments of uncertainty alongside moments of profound progress. Yet we must not be swayed by either excessive optimism or discouragement. Instead, with steady resolve, we should continue to advance stem cell research for the betterment of humankind, guided by rigorous science, ethical integrity, and a long-term vision for a healthier future.
Hideyuki Okano