Acknowledgements
This work was supported by the Ministry of Education, Science, and Culture of Japan under Grant-in-Aid number 20591263 (H.K.), the Kawano Masanori Memorial Foundation for Promotion of Pediatrics under Grant number 23-03 (H.K.), and the Japan Leukemia Research Fund under Award 2015 (H.K.).
Potential conflict of interest
Disclosure forms provided by the authors are available with the full text of this article online at https://doi.org/10.1080/10428194.2017.1387901.