Reciprocal surface expression of MHC class I and MICA between bone marrow- and pleural effusion-derived myeloma cell lines. (A) BM, PB, and PE myeloma cell lines were stained with isotypic mAb control (open curves) or with anti-MHC class I antibody (filled area). A clear overexpression of MHC class I molecule is detected in PE cell lines (1 of 5 representative experiments). (B) Staining obtained using BAM195 anti-MICA antibodies: MICA expression is detectable in BM cell lines but not in PE cell lines. Similar results were obtained using the anti-MICA-MICB antibody 6D4.