It is my great honor to serve as Guest Editor for International Journal of Gastrointestinal Intervention (IJGII) with Professor Shiomi. I would like to express my deepest gratitude to professor Dong Ki Lee and all members of IJGII for giving me this opportunity.

In this volume, we focus on the development of endoscopic ultrasound (EUS). As is well-known, EUS is now an essential modality not only for diagnosis but also for treatment of pancreato-biliary diseases.

These days, a variety of EUS-related procedures and their outcomes have been reported and the expectations for this area are only getting higher, whereas it has become more challenging for an endoscopist to gain knowledge on the real-world procedures and latest updates.

Given this background, our experts in this filed kindly reviewed existing literatures regarding recent development of these procedures. We deeply appreciate work of Professor Seo, Professor Kunda, Professor Teoh, Professor Lee, Professor Yasuda, Professor Cho, Professor Yamamoto, Professor Itoi and their co-authors. We have no doubt that this volume of IJGII is one of the best reviews that are currently available worldwide.

The COVID19 pandemic is still ongoing and thriving. It is our hope that things will return to normal soon and every one of you and your loved ones remain safe.

Finally, I hope that these reviews will help all the endoscopists gain better understandings of the procedure and improve the patient outcome.

With you a good read.