Inhibition of high molecular weight DNA fragmentation induced by TNF-α. (A) Lane 1, MW marker; 2 and 3, mock-transfected HL-60 cells; 4 and 5, HL-60 transformant NI-1 cells; 2 and 4, without, and 3 and 5, with rhTNF-α for 6 hours. (B) Lane 1, MW marker; 2 and 3, mock-transfected U937 cells; 4 and 5, U937 transformant NJ-1 cells; 2 and 4, without, and 3 and 5, with rhTNF-α for 6 hours.