ADVANCES IN GENETICS increases its focus on modern human genetics and its relation to medicine with the merger of this long-standing serial with MOLECULAR GENETIC MEDICINE. This merger affirms the Academic Press commitment to publish important reviews of the broadest interest to geneticists and their colleagues in affiliated disciplines. This volume of ADVANCES IN GENETICS continues the series goal to present both human and molecular genetic reviews in a timely fashion. Anderson and Kay investigate _CAB_ gene expression in the regulation of gene transcriptions in plants. Harmon and Allan offer a historical overview of apoptosis and its recent heightened interest. Developments involving four X-linked disorders and their resulting increased susceptibility to infection are presented by Smithand Notarangelo. Dickson and colleagues present research on the role of dystrophin in Duchenne muscular dystrophy and the potential feasibility of gene therapy in curing this disease as well as other diseases involving the heart and central nervous system. The relationship between mice and humans and the ways in which they help each other understand gene function and relationship is presented by Elizabeth Fisher. Timmons and Shearn summarize what information has been learned about _prune, Killer of prune_, and the _prune/Killer of prune_ lethal interactions: rare genetic phenomena in _Drosophila melanogaster_. Meiotic recombination, via the breaking and rejoining of DNA and the subsequent reciprocal exchange and the cytological evidence of the exchange, are explored by Ross _et al._ Last, Coonar and McKenna discuss the four major cardiomyopathies, focusing on recent advances in hypertrophic cardiomyopathy.