Schematic illustration of IFN-γ-mediated galectin-9 expression in HUVECs. In HUVECs, HDAC3 is involved in the constitutive expression of IRF3 and the p85α subunit of PI3K. Under IFN-γ treatment, HDAC3, PI3K, and IRF3 form a complex, leading to the phosphorylation of IRF3 at serine 386, which in turn activates galectin-9 expression.