Abstract: The present invention provides an isolated nucleic acid encoding KIAA0918, an isolated nucleic acid that hybridizes under high stringency conditions to a nucleic acid that is complementary to a nucleic acid encoding KIAA0918, a purified KIAA0918 protein, a purified protein encoded by a nucleic acid that hybridizes under high stringency conditions to a nucleic acid that is complementary to a nucleic acid encoding KIAA0918, a method of making KIAA0918 protein, an antibody specific for KIAA0918, a method for producing an antibody specific for KIAA0918 protein, a vector comprising a nucleic acid encoding KIAA0918, and a host cell transformed with a vector comprising a nucleic acid encoding KIAA0918. Also provided are methods for detecting the presence of and isolating hematopoietic stem cells in a heterogeneous cell suspension and for assessing gene expression in a tissue sample.