The second issue of the volume thirteenth of the year 2014 was published by the Iraqi Journal of Biotechnology, a special issue of the second international scientific conference held under the theme "The Role of Genetic Engineering in the Diagnosis of Diseases and Syndromes", October 15-16, 2014. The issue included twenty-seven researches in various biotechnological disciplines and their role in the diagnosis of genetic diseases and other in the diagnosis and detection of genes related to diseases and research on the diagnosis of pathogenic and environmental microorganism and some parasites that infect humans and animals by traditional and molecular methods and detection of some of their genes. The number also included research in the diagnosis of certain cancerous diseases and the use of cell lines in the study of pathogenesis of some types of cancer. Another research have also study the diseases that cause disorders of food metabolism such as diabetes, thyroid disease and related diseases such as polycystic ovary disease and its relationship with some genes. Many genes have been diagnosed with modern molecular methods. In the field of medicinal plants, the research dealt with some of the cytotoxic effects of hot crude extract of alovera plant on HePG2 tumor cell line.