There followed action brought by Sanofi-Aventis in the U.S., alleging Genentech's infringement of the two U.S. patents, and before the International Court of Arbitration (ICC), seeking the payment of outstanding royalties. The U.S. courts found in favour of Genentech, but Genentech was found liable by the ICC for the payment of the running royalties. The arbitral award meant that payments already made by Genentech under licence could not be reclaimed, and that payments due to Sanofi-Aventis were payable whether or not the patent had been revoked or infringed (despite the invalidity of the European patent), on the basis that the licence had been granted to allow Genentech to use the HMCV enhancer for the production of proteins without incurring risk of infringement action. (An interesting aside worth mentioning here is the ICC's consideration of the appropriate test for contractual interpretation.