From 30% to 50% of patients with RDD-harboring somatic mutations are frequently involved in ARAF, NRAS, KRAS, MAP2K1, CSF1, and CBL genes, of which MA2P2K1 and KRAS were the most frequent, making up 14% and 12.5% of all RDD, respectively (see Table 2) [51,52,53,54,55] (Table 2) Garces et al. showed mutually excluded KRAS and MAP21 gene mutations in RDD, together making up 33% of cases [38]. The gene discussed is MAP2K1; the disease is sinus histiocytosis with massive lymphadenopathy.