IGF1 and neoplasm: Finally, Taylor et al compared gene expression microarrays of tumor samples from SEPN (n = 3), supratentorial (n = 5), and posterior fossa (n = 21), and identified the expression signature for SEPN that consisted of 184 genes including HOX genes HOXA7, A9, HOXB6, B7, HOXC8, C10, and IGF1 [14].