Funding for this research was provided by:
Japan Agency for Medical Research and Development (JP18fk0108050)
Japan Society for the Promotion of Science (16KT0130, 17H04701, 17H05808 and 18H04895)
Ministry of Health, Labour and Welfare (H28-AIDS-General-001)
Inamori Foundation (NA)
Telecommunications Advancement Foundation (NA)
Core Research for Evolutional Science and Technology (JPMJCR1413)
Received: 18 December 2018
Accepted: 20 May 2019
First Online: 7 June 2019
Ethics approval and consent to participate
: The present study used data that are publicly available. As such, the datasets used in our study were de-identified and fully anonymized in advance, and the analysis of publicly available data without identifiable information does not require ethical approval.
: Not applicable.
: The authors declare that they have no competing interests.