Funding for this research was provided by:
the National Cancer Center Research and Development Fund (31-A-9)
Received: 14 July 2020
Accepted: 14 October 2020
First Online: 22 October 2020
Ethics approval and consent to participate
: The study protocol was approved by the Committee for Ethics of Animal Experimentation of the National Cancer Center (Japan) (K18-022). Experiments were performed according to the Guidelines for Animal Experiments (Science Council of Japan: Guidelines for Proper Conduct of Animal Experiments, 2006) and Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines.
: Not applicable.
: HH, NT and MI received experimental animals and borrowed an endoscope system from FUJIFILM Corporation, Kanagawa, Japan. There are no other competing interests to declare.