The fourth edition of 16th volume of the Iraqi Journal of Biotechnology was published in the fourth of December 2017, issued by the Institute of Genetic Engineering and Biotechnology for post Graduate Studies, The number contains twelve research papers in different fields of genetic engineering such as research about hormonal changes in women suffered from poly cystic ovary and the relationship between the disease and VIT.D receptor  issue contain paper about the molecular genetic diagnosis of some genes related to oligozoospermia  in male. Another study include the diagnosis of virulence factors in ecological  microorganism , more over study the  effect of physical factors such as gamma radiation and Laser on the cultivation and propagation of pathogenic bacteria , another study  about the role of human cytomegalovirus infection in Iraqi brain tumor