“… 21 , 22 Altogether, 42 cases (19%) with JAK2 mutations have been identified among a cohort of 242 children with ALL and DS. 21 - 24 Dr. William Carroll remarked that the same frequency has also been found in the Children’s Oncology Group DS ALL project (11 mutations of JAK2 (R683) in 59 samples). The correlations of JAK2 mutations and the presenting features or clinical outcome have yet to be defined.…”