Footnotes

• DG, JNL, TT and JCTL are joint first authors.

• JL, BT and JY are joint senior authors.

• DG, JNL, TT and JCTL contributed equally.

• Correction notice This article has been corrected since it published Online First. Author affiliations have been updated.

• Contributors JY, BT and JL conceived and directed the study. DG, AST, BT and JL collated and interpreted the data and performed biostatistical analysis. JNL, TT, SL and JCTL performed immunohistochemical techniques and scoring. DG and BT drafted the manuscript and final approval of all authors.

• Funding The authors received funding from A*STAR Career Development Award (C21112056).

• Competing interests None declared.

• Provenance and peer review Not commissioned; externally peer reviewed.

• Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.