TAP1 and neoplasm: In each tumor cell line, exposure to radiation significantly increased the expression of ≥ 6 APM components by ≥ 30%, namely the immunoproteosome subunits LMP2, LMP7, and LMP10; the peptide transporters TAP1 and TAP2; and the chaperones calnexin (2/3 cell lines) and tapasin (3/3 cell lines).