Transgenically expressed REX4 is exported into the host cell. Parasites expressing REX4-GFP showed uniform fluorescence in the host cell cytoplasm with some of the chimeric protein remaining inside of the parasite. Top, a ring stage infected RBC. Bottom, a RBC infected with two trophozoite stage parasites. Nuclei were stained with Hoechst; bf, bright field image. Bars, 5 mm.Spielmann T, Hawthorne PL, Dixon MW, Hannemann M, Klotz K, Kemp DJ, Klonis N, Tilley L, Trenholme KR, Gardiner DL. A cluster of ring stage-specific genes linked to a locus implicated in cytoadherence in Plasmodium falciparum codes for PEXEL-negative and PEXEL-positive proteins exported into the host cell. Mol Biol Cell. 2006 17:3613-24.