Isolated nucleic acids molecules, designated 69039 nucleic acid molecules, which encode novel Na⁺/Ca²⁺ exchanger members, are disclosed. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing 69039 nucleic acid molecules, host cells into which the expression vectors have been introduced, and nonhuman transgenic animals in which a 69039 gene has been introduced or disrupted. Isolated 69039 proteins, fusion proteins, antigenic peptides and anti-69039 antibodies are also disclosed. The invention further provides methods of treating, preventing and diagnosing hematopoietic and neurological disorders.