<正> Objectives:To isolate tumor metastaticsuppressing genes or relating human DNA sequencesand to study the molecular biological regulatingmechanism of tumor metastasis. Methods: HumanDNA fragments were amplified by Inter Alu PCRtechnique from normal human genomic DNAtransfected mouse tumor cell clones of which themetastatic phenotype had been suppressed. Thehuman origin of the amplified DNA was furtherconfirmed by PCR in situ hybridization. One DNA