Binding of Hp to Hb and uptake of the complex by the CD163 receptor expressed on macrophages. Hp-Hb binds the macrophage scavenger receptor CD163. On endocytosis the protein moieties of the ligand are degraded, whereas CD163 recycles to the cell surface. Heme is converted to the overall anti-inflammatory molecules CO, Fe²⁺, and biliverdin/bilirubin by HO-1 and the biliverdin reductase in the cytosol. In contrast to the Hp-Hb complex, the Hpr/TLF1-associated Hb does not bind CD163.