AbstractAmong the different biomarkers predicting response in chronic lymphocytic leukemia (CLL), the most influential parameters are the mutational status of the IGHV genes and the presence of TP53 gene disruptions. Nevertheless, these important assessments are not readily available in most centers dealing with CLL patients. To provide this molecular testing across the country, the Spanish Cooperative Group on CLL (GELLC) established a network of four analytical reference centers. A total of 2153 samples from 256 centers were analyzed over a period of 30 months. In 9% of the patients, we found pathological mutations in the TP53 gene, whereas 48.96% were classified as IGHV unmutated. Results of the satisfaction survey of the program showed a Net Promoter Score of 85.15. Building a national network for molecular testing in CLL allowed the CLL population a broad access to complex biomarkers analysis that should translate into a more accurate and informed therapeutic decision-making.