Nimmanapalli et al (2001) showed that the sensitising effect of imatinib to TRAIL in Bcr-Abl-positive leukaemia cells was reduced when TRAIL was administered after exposure to imatinib. Although imatinib causes cell cycle arrest, it is unlikely that this mechanism is involved in the reduced potentiation of MegaFasL-induced apoptosis by imatinib pretreatment, as Fas-mediated apoptosis is not cell cycle dependent (Hueber et al, 1998; Tepper et al, 2000). Here, FAS is linked to leukemia.