definiens: means, subject to the following sentence, the worldwide oncology business, operations, activities and programs of Seller andits Subsidiaries as of immediately prior to the Closing with respect to the discovery, research, development, manufacture, registration, commercialization, importation, distribution, sale and marketing of chemical or biological entities, pharmaceutical products, medicines, therapies, compounds, programs, or in vitro diagnostic or other devices, in each case, for patients in the areas of hematologic malignancies, solid tumors and other malignant diseases ( collectively, the ), including ( a ) all activities of Seller and its Subsidiaries as ofimmediately prior to the Closing related to ivosidenib ( TIBSOVO ® ), enasidenib ( IDHIFA ® ), vorasidenib, AG-270 and AG-636 and the productslisted in Section 1.1(b ) of the Seller Disclosure Schedules ( including as conducted through joint ventures, collaborations or similararrangements ) as of immediately prior to the Closing, and ( b ) any and all applications of such chemical or biological entities, pharmaceuticalproducts, medicines, therapies, compounds, programs or in vitro diagnostic or other devices in any field, including any Retained BusinessesField . Seller and Purchaser acknowledge and agree that the shall include only the business described in the immediately priorsentence and not any other businesses, operations, activities, compounds or programs of Seller or any of its Subsidiaries ( such otherbusinesses, operations or activities, the ), it being understood, notwithstanding anything to the contrary in the firstsentence of this definition of, the Retained Businesses shall include the businesses, operations and activities of Seller and itsSubsidiaries with respect to the discovery, research, development, manufacture, registration, commercialization, importation, distribution, saleand marketing of chemical or biological entities, pharmaceutical products, medicines, therapies, compounds, programs, or in vitro diagnosticor other devices, in each case for patients with rare genetic diseases and any other non - malignant diseases ( collectively, the ), including any chemical or biological entities, pharmaceutical products, medicines, therapies, compounds, programs or invitro diagnostic or other devices in Seller ’s rare genetic disease portfolio, including the products mitapivat and AG-946 and other PKR andPKM2 activators and inhibitors, together with ( i ) any other chemical or biological entities, pharmaceutical products, medicines, therapies, compounds, programs or in vitro diagnostic or other devices the medicines, therapies and programs relating to the Retained Businesses Fieldin pre - clinical development by Seller and its Subsidiaries and ( ii ) any and all applications of such items in any field, including the BusinessField