While differences in lung dysfunction and pathophysiological characteristics of ARDS/ALI from pulmonary and extrapulmonary sources have been intensively investigated, the role of genetic variants underlying these possible differences has not been thoroughly explored. Our data and its replication in three critically ill populations suggest that different injury-related genetic variants may contribute to susceptibility to ARDS/ALI from direct vs. indirect insults, lending support to the concept that ARDS/ALI is not a stereotyped response of the lung to injury. The identification of injury-specific genetic profiles may lead to a better understanding of the different pathways that lead to pulmonary dysfunction and may contribute  to the development of therapeutic interventions that target specific aspects of these disease processes. The inclusion of patients into these two genetically defined injury categories should be considered in the design of future trials in the study of ALI/ARDS. (By Dr.Paula Tejera, http://jmg.bmj.com/content/early/2012/10/08/jmedgenet-2012-100972 )