ZAP-70 is necessary for attachment of T cells under shear flow. (A) T lymphoblasts were untreated or treated with 10μM piceatannol and added to Ibidi chambers coated with 3 μg/mL ICAM-1 and 10 μg/mL E-selectin under a shear flow of 2 dyne/cm². Firmly adherent cells, all of which were migrating, are identified by dark phase images (arrows). (B) The T cells were categorized as rolling, transiently attached, or firmly attached and the interactions were quantified as a percentage of total interacting cells. The data, illustrated as dots, represent individual 3-minute videos pooled from 3 independent experiments.