Abstract: Methods of identifying homologous recombination activators are provided. These recombination activators can be use for gene therapy.

Abstract: Disclosed are methods for detecting mammalian genes encoding proteins which can function in microorganisms, particularly yeast, to modify, complement, or suppress a genetic defect associated with an identifiable phenotypic alteration or characteristic in the microorganism. Disclosed also are mammalian DNA sequences cloned by the above method, as well as polypeptide products of the expression of the DNA sequences in procaryotic or eucaryotic host cells and antibody substances which are specifically immunoreactive with said expression products. More specifically, the present invention relates to methods for cloning mammalian genes which encode products which modify, complement or suppress a genetic defect in a biochemical pathway in which cAMP participates or in a biochemical pathway which is controlled, directly or indirectly, by a RAS-related protein, to products (RNA, proteins) encoded by the mammalian genes cloned in this manner, and to antibodies which can bind the encoded proteins.

Abstract: The present invention relates to somatic mutations in the Multiple Tumor Suppressor (MTS) gene in human cancers and their use in the diagnosis and prognosis of human cancer. The invention further relates to germ line mutations in the MTS gene and their use in the diagnosis of predisposition to melanoma, leukemia, astrocytoma, glioblastoma, lymphoma, glioma, Hodgkin's lymphoma, CLL, and cancers of the pancreas, breast, thyroid, ovary, uterus, testis, kidney, stomach and rectum. The invention also relates to the therapy of human cancers which have a mutation in the MTS gene, including gene therapy, protein replacement therapy and protein mimetics. Finally, the invention relates to the screening of drugs for cancer therapy.