The Sonrisa de Daniela and Bubo Sports Events have donated euros 39,100 and euros 2,609.98, respectively to Translational Research in Child and Adolescent Cancer Group of the Vall d'Hebron Research Institute (VHIR) - euros 4,709 in total - to investigate Langerhans cell histiocytosis. It is a rare neoplasm that causes a wide spectrum of clinical manifestations, mainly inflammatory lesions ranging from relatively benign bone lesions to severe disseminated plaques. Histiocytosis can also lead to a neurodegenerative disease, which is usually progressive and sometimes lethal. A significant percentage of patients have relapses, most within the first two years after diagnosis.The Sonrisa de Daniela, a non-profit association named after a girl diagnosed with Langerhans cell histiocytosis in December 2016, has raised euros 39,100 to help drive disease research through various activities, such as booths, events and sales.Bubo Sports Events has contributed to VHIR euros 2,609.98 raised through the organization of races, such as the Family and Solidarity Race in the Pomar district, last September, and the Bada Trail night race, held last November: it allocated 1 euros of each participant's registration of to The Sonrisa de Daniela.Research on the monitoring of fluid biopsy histiocytosisThere is currently no consensus on the best follow-up for Langerhans cell histiocytosis. The euros 41,709 donated to Vall d'Hebron by La Sonrisa by Daniela and Bubo Sports Events will be invested in a research project of the VHIR that will scan the follow-up of histiocytosis by liquid biopsy (from blood or cerebrospinal fluid) and the detection of mutated DNA, specific to the cells altered in this pathology, to improve the prediction of clinical evolution of these patients."Histiocytosis is a rare and relatively poorly studied disease, which makes research approaches very necessary," says Dr. Luis Gros, Assistant Physician of the Pediatric Oncology and Hematology Service, and Researcher in the Translational Research in Child and Adolescent Cancer Group at the VHIR. "The potential of liquid biopsy in the monitoring of Langerhans cell histiocytosis is enormous and its clinical potential has only begun to emerge," says Dr. Josep Roma, principal investigator of the Translational Research in Child and Adolescent Cancer Group at VHIR. "However, comprehensive clinical implementation will only be feasible if validation studies such as those proposed by this research project are completed," says Dr. Constantino Sábado, associate doctor of the Pediatric Oncology and Hematology Service and researcher in the same group.