CXCR1 and acute myeloid leukemia: We then investigated whether IL-8 could have an impact on the cellular microenvironment instead of auto- or paracrine stimulation and found that out of all primary MSC investigated (n = 4, 2 from healthy volunteers and 2 from AML patients) a median of 9.7% of cells expressed IL-8 receptor CXCR1 on their surface, independently of the oxygen state they were in (increase 1.15fold in % positive cells, Fig. 4B).