RUNX2 and acute myeloid leukemia: IL-8 secretion was profoundly higher in primary AML samples as compared to AML cell lines (after 48 hours: 7.8 ± 9.1 [for Kg1a and OCI-AML3] versus 459.1 ± 644.4 pg/ml, p < 0.01), and induction of IL-8 expression at hypoxia of 1% O2 was also confirmed in the primary samples (2fold, p < 0.01: Fig. 3A).