Specifically, alterations in the B-Raf Proto-Oncogene, Serine/Threonine Kinase (BRAF), mitogen-activated protein kinase (MAPK), A-Raf Proto-Oncogene, Serine/Threonine Kinase (ARAF), and Rat Sarcoma Viral Oncogene Homolog (RAS) pathways have been identified in RDD, presenting potential therapeutic targets (6). The gene discussed is MARK2; the disease is sinus histiocytosis with massive lymphadenopathy.