A study at Vall d'Hebron has established a methodology to study the mutated protein in cystic fibrosis and the response to different treatments to allow the development of personalised therapies for the disease. The results have been published in https://www.nature.com/articles/s41598-021-94798-x Scientific Reports by the research group in Genetics Medicine of the Vall d'Hebron Research Institute (VHIR), the Clinical and Molecular Genetics Area and the Cystic Fibrosis Unit of the Vall d'Hebron University Hospital.Cystic fibrosis is a genetic and hereditary disease characterised by an affectation of the lungs with a variable severity. The pathology, with an incidence of 1/3,000-1/10,000 newborns, is caused by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. "There are more than 2,000 types of mutations in this gene and the analysis of the functionality of CFTR in each patient can help to understand the pathology and test the efficacy of existing modulatory drugs that partially restore the function of the altered CFTR protein", says Dr. Eduardo Tizzano, director of the Clinical and Molecular Genetics Area at Vall d'Hebron University Hospital, head of the Genetics Medicine research group at VHIR and co-author of the study.Although international researchers have worked to develop methods to analyse the functionality of CFTRs such as intestinal organoids, until now they have been complex, expensive and poorly reproducible. In the case of this work, nasosferoids, 3D cell cultures from nasal cells, have been used to reproduce what happens in the airways, which are mainly affected by cystic fibrosis.Vall d'Hebron researchers have worked to establish a new protocol to improve the reproducibility of the system, overcome some limitations and improve reliability. "Modulator treatments are expensive and the response may not be effective in some patients or sometimes not applicable because of rare gene alterations", says Dr. Silvia Gartner, coordinator of the Cystic Fibrosis Paediatric Unit, researcher of the Growth and Development group at VHIR and co-author of the study.To carry out the study, seven patients with cystic fibrosis controlled in the Cystic Fibrosis Unit with different genotypes and phenotypes of the disease and seven healthy people as controls were selected and analysed. To improve the protocol, the team made technical adjustments to increase the number of nasal cell observations to increase statistical power, analysed nasosferoids in greater depth and implemented the use of simple statistical analysis to examine nasosferoid responses.All of these protocol modifications will help improve the applications of nasospheroids for functional CFTR studies. Although they are artificial structures in culture, "the use of nasosferoids provides a simple, affordable and non-invasive approach to understand the function of patients' respiratory epithelium and to predict which patients will respond to modulatory therapy by aiding personalised therapy", concludes Dr. Tizzano.