Referee 2's review (Hideaki Senzaki):
This is an elegant study extending the authors' previous findings indicating that RNA virus infection possibly causes Kawasaki disease. The paper is very well written; well hypothesized, data clearly presented, and reasonably discussed. The only comment I would suggest is about the percentage of Kawasaki disease patients with ICI positive lung tissue. Previous studies (infants) and the present study indicate that ICI were found in most, but not all of Kawasaki patients. If the RNA virus infection in the lung is the cause of Kawasaki disease, then the ICI positive rate should be a 100 %. Is this due to methodological limitations, misdiagnosis of Kawasaki disease or etiological mechanism other than RNA virus infection? Please comment on this issue.
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N.B. These are the comments made by the referee when reviewing an earlier version of this paper. Prior to publication the manuscript has been revised in light of these comments and to address other editorial requirements.
