B2M and neoplasm: In addition, for within the cell, antigen processing, transport, presented protein molecules, such as MHC class I molecules, β2M (Beta 2 microglobulin), LMP (Large multifunctional protease), and the TAP (Transporter associated with antigen processing) is a tumor antigen processing and/or presented important component, when encoding their genetic change can also lead to the ICB resistance.