Contents -- Preface -- History of the Problem -- Hybrid Cells Receiving Methods and Mechanism of Cells' Fusion -- Geno- and Phenotypic Characteristics of Hybrid Cells -- Utilization of Somatic Hybridization in Biology and Medicine -- Etiology and Pathogenesis of Cancer -- Factors, Induced the Malignant Process -- The Theory of "Two Synkaryons" -- Experimental and Clinical Confirmations of the "Two Synkaryons" Theory -- Explanation of Different Complicated Aspects of the Experimental and Clinical Oncology from the Standpoint of the "Two Synkaryons" Theory -- Etiology and Pathogenesis of AIDS -- Possible Common Etiology and Pathogenesis of Cancer and AIDS -- A Possible Reason for the Interrelation of Some Malignant Tumors and AIDS -- A Paradoxical Idea of Cancer's Resolution -- Summary -- Index.