Retrieved from http://www.reactome.org/pages/about/license-agreement/ on 2016-04-02.
Reactome is a free and open-source project, and you are free to download Reactome software and data. The contents of Reactome are copyright (c) 2003-2016 Cold Spring Harbor Laboratory (CSHL), Ontario Institute for Cancer Research (OICR) and the European Bioinformatics Institute (EBI). The software and information contents are distributed under the terms of the Creative Commons Attribution 4.0 International License, which grants parties the non-exclusive right to use, distribute and create derivative works based on Reactome, provided that the software and information is correctly attributed to CSHL, OICR and EBI.
More details about the Creative Commons License is available here.
KEGG gene and pathway annotations, used to construct the Reactome Functional Interaction (FI) Network, are provided under license to OICR by Pathway Solutions, Inc. The Reactome FI Network data set is intended for use only by the original recipient. The recipient may not distribute this data to other users without a license from Pathway Solutions, Inc.