definiens: means, with respect to any Licensed Product follo wing its First Commercial Sale, the aggregate gross amount invoiced or received by Licensee, any Affiliate or its or their sublicensee ( s ) ( each, a ), for sales of such Licensed Product by a Selling Party to any Third Parties, less, to the extent customary and reasonable and specifically and solel y allocated to the sale of such Licensed Product an d actually taken, paid, accrued, allowed, included, or allocat ed, based on good faith estimate as permitted by U. S. GAAP and consistent with such Selling Party ’s practice ( and consistently applied as set forth below ): [ * * * ] Net Sales will be determined from books and records maintained in accordance with U.S. GAAP, consistently applied by Licensee and its Affiliates or its or their sublicensees . Sales between Licens ee and its Affiliates and sublicensees shall be disregarded fo r purposes of calculating Net Sales, except if such purchaser is an end user ; and, in such event, Net Sales shall be calculated on the basis of the average sales price to unaffiliated Third Parties in the respective Calend ar Year