CT antigen expression in week 42 placenta. Hematoxylin-eosin staining (A1, B1, C1, D1) of villous parenchyma (A1-B9) and basal plate (C1-D9). Negative immunohistochemical staining with mAb MA454 to MAGE-A1 (A2, B2, C2, D2), mAb CT7-33 to CT7/MAGE-C1 (A5, B5, C5, D5), mAb ES121 to NY-ESO-1 (A6, B6, C6, D6), mAb #23 to GAGE (A7, B7, C7, D7), and mAb CT10#5 to CT10/MAGE-C2 (A8, B8, C8, D8). Homogeneous mAb M3H67 immunostaining of placental villous parenchyma (A3) comprising cytotrophoblast and syncytiotrophoblast (B3) and circumscript intense labeling of basal plate (arrows) (C3) resembling extravillous trophoblast cells (D3). Heterogeneous immunostaining with mAb 57B to MAGE-A4 (A4) involving small areas of villous cytotrophoblast and syncytiotrophoblast (B4) and focal areas of extravillous trophoblast (D4) of the basal plate (C4). Negative mAb 4H84 immunostaining of the villi (A9, B9) is seen next to intense immunoreactivity of the extravillous trophoblast of basal plate (C9, D9).