First I was very surprise to see that we had 1 unique reviewer and his first statement was that the topic was complex (so obviously not someone from the field). He made a lot of criticism but we were able to make corrections and provide more data. After a first round, the reviewer was still unsatisfied and ask for more experiment to be done (that were not asked at first). Even though surprising, we have done all the corrections required by the referee but he finally decided to reject the paper for an unclear reason ("the work has no clear focus (???)") . Anyway, having 1 biased reviewer just demonstrates the poor rigour of the journal.