PTPN11 and melanoma: Another recent study screened 20 desmoplastic melanomas by exome sequencing for alterations in the MAPK and PI3K signalling pathways, i.e. mutations in CBL, ERBB2, MAP2K1, MAP3K1, BRAF, EGFR, PTPN11, MET, RAC1, SOS2, NRAS and PIK3C, which were found in 15/20 (75%), with NF1 mutations being found in 9/20 (45%) [61].