Hsp90 inhibitors induce apoptosis in CLL cells that express adverse prognostic markers. (A) Cell apoptosis was measured in CLL cells (n = 25) after in vitro treatment with 17-AAG at 100 nM during 48 hours. IgV_H gene mutation was assessed by gene sequencing. Sequences with less than 98% homology to the corresponding germ-line IgV_H sequence were considered mutated. (B) Correlation by linear regression of the level of expression of ZAP-70 and apoptosis induced by 17-AAG (100 nM) after 48 hours of incubation in CLL samples. (C, D) Cell death was assessed in ZAP-70⁺ CLL cells after treatment with 17-AAG, 17-DMAG, and EC116 using 100 nM at different time points and also during 48 hours using increasing concentrations.