The experimental design is very good and properly described.
Validity of the findings
The finding are very well supported and the iconography is excellent!
Comments for the author
I agree that the author have demonstrated that endothelia covering-type extravasation happens in absence of VEGF and therefore is likely to be one of the factors allowing tumour progression under anti VEGf treatment. I also agree that they have demonstrated that more cells extravasate. I am only doubtful whether this account for a more aggressive tumour as, after all, the invasion type is instead absent absent. Perhaps the author could briefly comment on this issue instead of concluding that could explain a more aggressive behaviour.