Fig. 2 |. Developmental origins of childhood cancer.

a, Progression of human development from embryo to childhood. Oncogenic mutations may occur in the prenatal period, but cancer only emerges at a later developmental time point. This principle has been well described in childhood leukemias. b, Myeloid differentiation, from HSC, to common myeloid progenitor (CMP), granulocyte monocyte precursor (GMP) and differentiated myeloid cells. The cell of initial mutation for AML is an earlier stem cell, while the AML cell of origin is a more differentiated precursor cell. c, Oligodendrocyte maturation, from neural stem cell (NSC) to OPC and mature myelinating oligodendrocyte (OL). Childhood gliomas may arise from precursors in the oligodendroglial lineage (pre-OPC or OPC). While the timing and cell of mutation for each pediatric glioma subtype is not yet clear, some evidence suggests that the key oncogenic mutations may occur at an earlier developmental time point .