Fluorescence stereomicroscopic comparison of donor cell distribution at 48 hours postinjection of PKH-67–labeled bone marrow cells. (A) Fetal abdomen after IP injection; (B) fetal thorax after IP injection; (C) fetal abdomen after IC injection; and (D) fetal thorax after IC injection. Note the persistence of donor cells in the peritoneal cavity and paucity of engrafted donor cells in the fetal liver after IP injection. In contrast, the fetal liver and intercostal vascular bundles have large numbers of engrafted and circulating PKH-positive cells following IC injection. H, heart; FL, fetal liver; I-Cv, intercostal vessels. See Figure 4 in the article by Vrecenak et al that begins on page 1987.