SUMMARY Cystic fibrosis is the most common inherited disease in the European population, which significantly shortens the lifespan. Another term used for the disease is mucoviscidosis which describes the consequences of the disease - a thick and viscous mucus and secretions in the respiratory tract and other organ involvement. The clinical picture of cystic fibrosis is the result of changes in the external secretion glandular activitywhich causes damage to many organs, but most respiratory, digestive and reproductive system. Symptoms and severity vary considerably in different patients. Digestive symptoms are caused mainly by pancreas diseasewhich leads to insufficient level of enzyme for normal digestion of food which causes diarrhea and malnutrition. The respiratory system does not work properly also, so the secretion in the airways is thick, wiry and more abundant than normal. Due to changes in characteristics of secretions in the reproductive organs, male patients are due to clogged deferens usually infertile. OBJECTIVE Cystic fibrosis is a monogenic disease caused by mutations in a specific gene, CFTR gene. The pathophysiology of the disease is very well described and therapeutic goals are clear. Furthermore, the diagnosis of the disease is based on genetic testing to identify the type of disease and to determine the precise genetic defect in each case (M. D. Amaral, 2015). Despite the fact that cystic fibrosis seems to be a "simple" monogenic diseaseat first glance, it is also a complex pathophysiological condition. The aim of this paper is to describe the molecular mechanisms of cystic fibrosis and disorders caused by the disease, describe the importance of personalized medicine and explore, consolidate, develop and present the achievements in the development of drugs to target treatment of certain classes of mutations that lead to the appearance of cystic fibrosis. MATERIALS AND METHODS The discovery of the gene that causes cystic fibrosis has led to a better understanding of the various mutations and pathophysiological events. These findings led to the development of potential new therapies that target the basic defect (M. Wilschanski, 2012). Therapeutic approaches that target the basic defect can be divided into two very different approaches: gene therapy focused on the repair of genetic disorders and molecular therapy, based on the correction of functional defects at the protein level (E. Q. Gallego et al., 2014). Gene therapy has focused on the introduction of normal copies of the gene in patients with cystic fibrosis. Unlike gene therapy, molecular approach, i.e., therapy directed to the return of lost function of the CFTR protein, showed significant results that led to the development and ultimately, approval of the first drug that directly targets the CFTR protein in January 2012 when it was released on the US market. Certain types of therapy and current achievements in the treatment of the symptoms of cystic fibrosis as well as the paths that led to significant findings are described further in paper. DISCUSSION The goals of personalized medicine are focused on the medical risks assessment and the monitoring, diagnosis and treatment of patients according to their specific gene composition and molecular phenotype (M. D. Amaral, 2015). This "simple" monogenic disease is caused by mutations in the CFTR gene, a form of the disease is influenced by many additional factors such as the specific biological pathways and environmental conditions that are difficult to assess (M. D. Amaral, 2015). Furthermore, every person with cystic fibrosis is unique and requires a personalized diagnosis which makes all the knowledge and experience of genetic variation as well as the ex vivo impact assessment very important for a personalized approach to treating this disease (M. D. Amaral, 2015). Understanding the precise mechanisms of action of CFTR booster and rectifier is much higher than a few years ago but still insufficient. The reason for many uncertainties is the biological complexity of the CFTR protein and its interactions with other molecules which represents a major challenge to scientists (M. Brodlie et al., 2015). CONCLUSION Cystic fibrosis can serve as a paradigm for the potential application of personalized medicine on other respiratory and genetic disorders. Previous discoveries and successes gave hope to those suffering from cystic fibrosis for a better and potentially longer life. Despite the need for further research on the return of the CFTR protein function, the current results show that this is certainly a realistic and achievable goal.