From a clone mapping to human chromosome 22q13.3, we have identified NPAP60L, the human homolog of the rat nuclear pore-associated protein gene, Npap60. The expression pattern of the human copy is much more complex that that of the rat, although conservation of the potential specific function of NPAP60L in male germ cells can be seen for one of the five transcripts. The exon-intron organization of the NPAP60L gene shows the presence of at least three alternate 3' ends, and Northern analysis indicates the possible presence of alternate 5' ends. Somatic cell hybrid mapping revealed additional related copies of NPAP60L on human chromosomes 5, 6, and 14, although it is not known if these are functional genes.