Adhesion of K562-Lu cells to laminin and Lu-gp phosphorylation (P) during exposure to HU. (A) Data are mean ± SEM values of K562-Lu cells adhering to laminin at 2 dyn/cm² before (Control) and after 24 and 48 hours of exposure to 250μM HU (n = 3). (B) Lu-gp phosphorylation of HU-treated K562-Lu cells (typical result); data (mean ± SEM) at 24 and 48 hours were 0.75 ± 0.27 and 0.27 ± 0.1, respectively (n = 3). HU exposure reduced K562-Lu adhesion to laminin and Lu-gp phosphorylation.