OS and disease progression of LCH patients in this series by tumor genotype. (A) Kaplan-Meier analysis of overall survival stratified by presence of BRAFV600E, MAP2K1 mutation, or neither mutation (P < .66). (B) Percentage with progression or recurrence: MAP2K1-wt vs MAP2K1-mut, P < .1267 (i); BRAFV600E vs MAP2K1-mut, P < .0360 (ii); and BRAF-wt/MAP2K1-wt vs MAP2K1-mut, P < .4837 (iii).