Lim JH, et al. - In this first study surveying whole genes and microRNAs (miRNAs) in placentas of trisomy 21 (T21) fetuses, authors attempted to ascertain the integrative association between genes and microRNAs. They examined the expressions of genes and microRNAs in the whole genomes of chorionic villi cells from normal and T21 human fetal placentas. Using bioinformatics tools, the functional significances and interactions of the genes and microRNAs were predicted. Results revealed that 17 genes and eight miRNAs were differentially expressed between euploid and T21 fetuses and they were negatively regulated in T21. They suggested that many biological pathways that have been implicated in T21 and its complications are possibly regulated by these genes.