Addressing these inequalities will require a better understanding of who these children are, their vulnerabilities and the challenges they will face as they transition through adolescence into adulthood. One in five lives in the 48 countries defined by the United Nations as least developed (34 in sub-Saharan Africa, 13 in Asia and the Pacific, and one in Latin America and the Caribbean), where the challenges to the fulfilment of their potential are the greatest and the institutions to support them are the weakest. Greater levels of gender inequality have higher Gils.