XIST and neoplasm: Of all the cancer-associated genes identified including, somatomedin B and thrombospondin type 1 domain containing [SBSPON], carboxypeptidase X, M14 family member 2 [CPXM2], XIST, tubulin beta class I [TUBB], transmembrane 4 L six family member 1 [TM4SF1], to our knowledge only NTRK2 has been specifically linked to tumours of neural crest origin.