Two patients had PVs in two CPS genes: a patient with LCH had PVs in BRCA2 and AXIN2; a patient with a malignant peripheral nerve sheath tumor had PVs in NF1 and PALB2. All CPS PVs were monoallelic, except for one patient with biallelic PVs in DDX41.[39]. This evidence concerns the gene DDX41 and Langerhans cell histiocytosis.