Proposed model for P vivax development in the bone marrow. (A) P vivax infects stage III reticulocytes that have egressed by diapedesis to the sinusoidal capillary lumen. Alternatively, P vivax merozoites or P vivax–infected erythrocytes might enter the red bone marrow compartment, leading to invasion of CD71⁺ reticulocytes. Accelerated reticulocyte aging increases host cell deformability for subsequent endothelial crossing toward blood circulation. Adapted from Figure 5 in the article by Malleret et al that begins on page 1314. (B) Proposed model for P falciparum development in the bone marrow. Presence of immature gametocytes in the bone marrow extravascular space may be explained by erythrocytes infected by stage I gametocytes or sexually committed ring stages entering the bone marrow stroma through the endothelial lining. Alternatively, asexual schizonts, which develop in the extravascular compartment, may produce sexually committed merozoites that invade erythroid precursors, whose remodeling may share possible similarities with that of P vivax. Mature gametocyte-infected host cells cross the endothelial barrier to reenter the circulation. Adapted from supplemental Figure 7 in Joice et al.⁷  Professional illustration by Patrick Lane, ScEYEnce Studios.