We and others previously pointed to the importance of the cytokine RANKL in fibrous dysplasia(5), and this lead to the development of targeted therapies, first in preclinical and compassionate treatment case studies (6,7,27–29) and then in a clinical trial(8,9), including ongoing studies (https://clinicaltrials.gov/study/NCT05419050). The gene discussed is TNFSF11; the disease is fibrous dysplasia.