 Prostratin was isolated in a concoction made from the bark of the local mamala tree ("Homalanthus nutans") and shared with him by a healer named Epenesa Mauigoa, who used it to treat hepatitis.Cox set up royalty agreements to ensure that the Samoans will share in the revenue.In 1988, his research was threatened when the Samoan government pressured the village of Falealupo to pay $85,000 for a new school, warning that if the village did not provide a new school within a year, they would withdraw the teachers from the village, leaving the children without an opportunity for a formal education.