RB1 and malignant peripheral nerve sheath tumor: Three patients had positive ctDNA results, including one patient (INDIA 1280) with a benign neurofibroma of the right femoral nerve that had a GOLGA2 splice site acceptor mutation at a mutant allele frequency (MAF) of 0.19%, and two MPNST patients (INDIA 1244 and INDIA 1281) that a RB1 R787Qfs*23 mutation at 2.55% and a TP53BP2 A324V mutation at 0.04%, respectively.