Funding for this research was provided by:
National Research Foundation of Korea (2013R1A6A3A04059017, 2018R1A2B6004608)
National Cancer Center (NCC-1810220-01)
Received: 8 February 2019
Accepted: 7 January 2020
First Online: 14 January 2020
Ethics approval and consent to participate
: This study was approved by the institutional review board (IRB) at the Seoul National University (IRB approval number: SNU IRB No. E1503/002–004).
: Not applicable.
: The authors declare that they have no competing interests.