Nature Immunology 4, i (2003).

In the cover caption of the December 2003 issue of Nature Immunology, the second sentence should read “This 2-day-old embryo illustrates how one can monitor multilineage hematopoiesis in living zebrafish after transplantation of transgenic donor marrow carrying red (eyrthocytes; gata1dsRED) and green (leukocytes; bactineGFP) fluorescent markers.” The credit should read “Digital image by D. Traver.”