Nature Immunology 5, 169–174 (2004).

Citation of two papers was accidentally omitted. The paper by Hiraiwa, M., Soeda, S., Kishimoto, Y. & O'Brien, J.S. Binding and transport of gangliosides by prosaposin. Proc. Natl. Acad. Sci. USA 89, 11254–11258 (1992) should have been cited instead of reference 24 on page 171, last paragraph, first sentence. The paper by Christomanou, H., Chabas, A., Pampols, T. & Guardiola, A. Activator protein deficient Gaucher's disease. A second patient with the newly identified lipid storage disorder. Klin. Wochenschr. 67, 999–1003 (1989) should have been cited instead of reference 22 on page 169, second column, top paragraph and on page 173, first column, top paragraph, last sentence.