[Alterations of oncogenes in human cancers].

A lot of alterations of oncogenes have been reported to occur in human cancers in vivo. The types of alterations which occur most frequently are point mutations of ras genes, amplifications of myc and erbB gene families and rearrangement of oncogenes by chromosomal translocation. Each type of gene alteration discloses the specificity not only to organ and cell types from which cancer originated but also to etiological background and clinical aggressiveness of cancer. These gene alterations are shown to activate oncogenes and suggested to be involved in the mechanism of genesis and/or progression of human cancers.