 The inhibitor demonstrated a remarkable response in tumor regression and in hematologic improvement.Based on these results, phase I and later phase II clinical trials were then conducted in children with inoperable NF1-related plexiform neurofibromas, using Selumetinib, an oral selective MEK inhibitor used previously in several advanced adult neoplasms.The children enrolled in the study benefited from the treatment without suffering from excessive toxic effects, and treatment induced partial responses in 72% of them.