This week’s International Meeting for Autism Research was filled with important presentations on the multiple causes of autism, interventions, diagnosis, neurobiology, services, family and self-advocate perspectives, the list goes on and on. There is a great recap on www.spectrumnews.org. An underlying theme ran through the presentations. That is, that the previous “well, we don’t see differences because there is lots of heterogeneity in autism” explanation isn’t cutting it anymore. We know people with autism are different, and parents, self-advocates and researchers are starting to deal with it by stratifying groups by their genetic backgrounds. While not a complete solution to this challenge, research at IMFAR shows that identifying different subgroups based on genetics is helping to explain symptoms.