The αGal1 mAb 8F4F8G7 inhibits rGal1-induced apoptosis of in vitro–activated T cells. αCD3/CD28–activated human T cells were treated with 10μM rGal1 alone or 10μM rGal1 preincubated with 5μM αGal1 mAb (8F4F8G7) or an isotype-matched IgG2bλ control, and evaluated thereafter with a flow cytometric apoptosis assay (annexin V–FITC and propidium iodide staining). The percentage of cells in each quadrant is indicated (A). The histogram summarizes the percentage of annexin V⁺ cells in the absence of rGal1 or in the presence of rGal1 alone or rGal1 preincubated with the αGal1 mAb or the isotype control (B).