Clinical outcome of patients with pediatric LCH according to mutational status and disease extent. Kaplan-Meier curves showing EFS according to lesional BRAF^V600E status for all 373 patients (A), 339 patients with low-risk LCH (B), 285 patients with SS LCH (C), or 183 patients with SS-UFB LCH (D) at diagnosis. Patients with low-risk LCH comprise all patients except those with high-risk (MS-RO⁺) disease. Kaplan-Meier curves showing EFS of patients with BRAF^V600E, BRAF exon 12, or MAP2K1 mutations (E-F). Curves are shown for all 282 patients (E) and for 141 patients with SS-UFB LCH (F) at diagnosis. Four patients without clinical follow-up were not included in these survival analyses. pos, positive; neg, negative.