Topic 606 supersedes all previous revenue recognition requirements in accordance with generally accepted accounting principles. This standard applies to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. Under Topic 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration to which the entity is entitled to in exchange for those goods or services. To determine revenue recognition for arrangements that we determine are within the scope of Topic 606, we perform the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) we satisfy a performance obligation. We only apply the five-step model to contracts when it is probable that we will collect the consideration we are entitled to in exchange for the goods or services we transfer to the customer. Revenue On January 1, 2018, we adopted ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (Topic 606) using the modified retrospective method applied to those contracts that were not completed as of January 1, 2018. Results for the six months ended June 30, 2018 are presented under Topic 606, while prior period amounts are not adjusted and continue to be reported in accordance with our historic accounting under previous revenue recognition guidance, Accounting Standards Codification Topic 605: Revenue Recognition (Topic 605) . The adjustments due to the adoption of Topic 606 primarily related to a reduction in deferred revenue driven by the allocation of the transaction price to our license performance obligations in the Ipsen and Takeda collaborations, which were determined to be functional intellectual property that