CD160 activates the PI3K/AKT signaling pathway. CLL cells (5 × 10⁶/mL), MEC-I cells (10⁶/mL), and Sanchez cells (10⁶/mL) were pretreated with or without 1μM wortmannin for 1 hour and then incubated with 10 μg/mL BY55 for the indicated times. Akt and phosphorylated Akt protein expression was detected by Western blot. The β-actin expression acted as a loading control.