Catteruccia et al. announce in the June 22 Nature that they have succeeded in introducing DNA into the germline of Anopheles stephensi, the mosquito that is one of the major carriers of malaria in urban areas of the Indian subcontinent (Nature 2000, 405:959-962). They injected two plasmids (one with a gene for green fluorescent protein (GFP) and the other with a transposase gene) into mosquito eggs. The eggs were treated with an inhibitor of melanization to slow hardening. Five of 69 surviving adults (7%) incorporated the GFP-encoding DNA into their genomes and fluoresced. Transformation should allow the introduction of genes that prevent reproduction of the malaria parasite within its obligatory insect vector.