Alternative splicing is important for contributing to the diversity of protein in eukaryotic world.About 50%-75% of the human genes are regulated by alternative splicing not only in different developmental stages but also in various physiological and pathological processes.However,it is still unclear whether alternative splicing regulation of the human genes are involved in cellular responses to hypoxic insults.To address this question,we performed a genome-wide analysis of the alternative splicing regulation using the exon array technique to evaluate the differentially expressed transcript variants of all of the human genes in the endothelial cells exposed to hypoxic insults induced by CoCl2.In brief,the GeneChip Human Exon 1.0 ST Array (Affymetrix Inc.) was used to identify the differentially expressed isoforms in the human umbilical vein endothelial cells (HUVEC) in hypoxic insults.