His Excellency, Peter Gregory Onwubuasi Obi has celebrated one of the best brains in Nigerian economic department, Ngozi Okonjo-Iweala as she turns 70th birthday. He wrote below : “I would like to celebrate my Very Dear Elder Sister and Director General of the World Trade Organisation, Dr Mrs Ngozi Okonjo-Iweala @NOIweala, as she marks her 70th birthday