At Will Employment. You should be aware that your employment with FibroGen is for no specified period and constitutes "at-will" employment. As a result, both FibroGen and you are free to terminate the employment relationship at any time, for any reason or for no reason, and with or without advance notice. The changing needs of FibroGen could also result in changes to certain aspects of your employment, such as compensation, responsibilities, location, etc. These provisions expressly supersede any previous representations, oral or written. Your at-will employment cannot be modified or amended except by written agreement signed by both you and the Chair of the Board of Directors of FibroGen.