Requirements for direct contact with ECV-304 endothelial cells for the inhibition of apoptosis in B-CLL cells.

B-CLL cells were cultured for 1 and 3 days in 4 conditions: CM, ECCM, ECV-304 cells + B-CLL cells (direct contact), ECV-304 cells and B-CLL cells separated in a transwell (Transw) system. A gate for lymphoid cells was established to exclude contaminating ECs. Statistical analysis was carried out using analysis of variance with n = 9, and P < .05.