NF1 and malignant peripheral nerve sheath tumor: For instance, immune genes such as HLA, which encode MHC class I and II, the transcription factor MHC II transactivator (MHC2TA), the transporter associated with antigen processing (TAP1), and the related chaperone CD74, show reduced expression in NF1-associated tumors compared to normal human Schwann cells highlighting downregulation of or impaired antigen presentation processes in MPNST [103].