A new study on Autism released Tuesday reveals 18 new candidate genes. Previously, researchers had identified 42 genes that they knew played a role in the cellular processes that caused autism, according to Spectrum.

The study, published in Nature Neuroscience, was the largest study of whole genomes ever done. More than 5,000 people were studied who either had autism or had a child or sibling that did. In other words, the researchers looked at the genes of people who are in families with autism spectrum disorder, according to the study.

The result was the identification of 61 genes total that were linked to autism. Of those 61 genes, 49 were important for RNA processing. The mutated genes ended up being identified as the ones that caused behavioral aspects of autism while it’s the deletion or duplication of genes that caused cognition levels to be lower.

Understanding better which genes deletions or mutations cause the different aspects of autism allows researchers to further isolate and study those genes in the hopes of developing better treatment methods for the future.