Yong, K
Cavet, J
Johnson, P
Morgan, G
Williams, C
Nakashima, D
Akinaga, S
Oakervee, H
Cavenagh, J
Article History
Received: 6 July 2015
Revised: 12 October 2015
Accepted: 26 October 2015
First Online: 22 December 2015
Competing interests
: D Nakashima and S Akinaga are employees of Kyowa Hakko Kirin Co. Ltd (Tokyo and USA). The other authors declare no conflict of interest.