To examine the effect of hypoxic conditions on KL-6 expression in BC cells, CoCl2, a chemical hypoxia inducer, was used to treat the cells, and changes in the expression of the hypoxia markers LOX-1 and HIF-1α, as well as KL-6, were evaluated by immunofluorescence staining (Fig. 7A). This evidence concerns the gene OLR1 and breast cancer.