(f) HeLa cells were transfected with plasmids encoding GFP-IRGMd and were stained with antibodies against HMGB1 (absence of nuclear HMGB1 stain is a marker of HMGB1 release) or DAPI. Top: images indicate GFP-IRGMd (left), HMGB1 (middle) and DAPI (right) localization. Bottom: phase-contrast microscopy image of cells (left) and image merged from other panels (right). Scale bars, 5 μm. 