Overview.- Pathobiology of Human Germ Cell Neoplasia.- Cells of Origin.- Carcinoma in Situ of the Testis: Possible Origin, Clinical Significance, and Diagnostic Methods.- Characterization of Precancerous and Neoplastic Human Testicular Germ Cells.- Cytogenetic Investigation of Gonadal Carcinomas in Situ in Syndromes of Abnormal Sexual Differentiation.- Cell Lines.- Human Embryonal Carcinoma and Yolk Sac Carcinoma in Vitro: Cell Lineage Relationships and Possible Paracrine Growth Regulatory Interactions.- Biochemical Analysis and Cellular Location of the GCTM-2 Antigen in Embryonal Carcinoma and in Other Tumour Cell Lines.- Differentiation Antigens.- The Surface Antigen Phenotype of Human Embryonal Carcinoma Cells: Modulation Upon Differentiation and Viral Infection.- Lactate Dehydrogenase Isoenzyme 1 in Testicular Germ Cell Tumors.- Expression of Developmentally Regulated Genes in Embryonal Carcinoma Cells.- Chromosomal Studies.- Cytogenetic Studies of Testicular Germ Cell Tumors: Pathogenetic Relevance.- Isochromosome (12p) in Germ Cell Tumors.- Molecular Genetics.- Molecular Analysis of Isochromosome 12p in Testicular Germ Cell Tumors.- Analysis of Chromosome 12 Abnormalities in Male Germ Cell Cancers.- Frequent Occurrence of Activated ras Oncogenes in Seminomas but Not in Nonseminomatous Germ Cell Tumors.- Differential Activation of Homeobox Genes by Retinoic Acid in Human Embryonal Carcinoma Cells.- Growth Factors and Their Receptors.- Growth Factors and the Control of Human Teratoma Cell Proliferation.- Role of Heparin-Binding Growth Factors in Embryonic Tumors.- Growth Factors and Receptors During Differentiation: A Comparison of Human and Murine Embryonal Carcinoma Cell Lines.- Growth Factors in Human Germ Cell Cancer.