Dengue is currently the most common insect-borne viral disease of humans worldwide. Scientists from the Institut Pasteur, the French National Center for Scientific Research (CNRS), and the Armed Forces Research Institute of Medical Sciences (AFRIMS) have discovered several genetic factors controlling the transmission of various dengue virus strains in a natural population of mosquitoes in Thailand. Their results indicate that the transmission of these viruses in nature depends not only on mosquito genetic factors but also on their specific interaction with viral genetic factors. This discovery significantly advances our understanding of dengue biology in nature. From a more general standpoint, this study also refines our view of the genetic basis of host-pathogen interactions. This work was published August 1st, 2013 on the PLoS Genetics website.