Text and Data Mining valid from 2018-02-05
Received: 11 August 2017
Accepted: 5 January 2018
First Online: 5 February 2018
: All the authors are currently employed by British American Tobacco (Investments) Ltd, and the study was funded by British American Tobacco (Investments) Ltd. Elements of this work were conducted at Source Bioscience Ltd, Fios Genomics Ltd and Epithelix Sarl as part of a commercial contract.