The article “Seeded QED cascades in counter-propagating laser pulses” published in Physical Review E in 2017 by Thomas G, Marija V, Joana M, Ricardo F and Luis OS has been selected for a Physical Review E (PRE) Spotlight on Laser-created Pair Plasmas. Each PRE Spotlight represents a small selection of articles, dealing with the same research area. The article provides an exhaustive study about the growth rates of QED cascades in counter-propagating lasers. In addition to the new analytical work developed by the authors, all recent existing theoretical models for the growth rate from other authors are shown and compared to first-principles QED-PIC simulations. A discussion about the cascade’s threshold is included, based on the analytical and numerical results. The paper is available here.