B2M and neoplasm: Other causes of an immunologically ignorant/exclusive TIME, including deficits in tumor antigen presentation/tumor cell recognition through the loss of MHC I expression and/or the downregulation or inactivation of beta-2 microglobulin (B2M), a component of the MHC class I complex in the TME; impaired T cell extravasation and tumor infiltration through various routes of chemokine modulation; and tumor intrinsic factors, such as galectin-1, are also identified in NSCLC [97,98,99,100,101,102,103,104,105,106,107].