Fig. 4.

Effects of IFNγ in combination with exogenous growth factors on in vitro AML blast proliferation. AML blasts from 65 consecutive patients were cultured in the presence of either IL1β, SCF, GM-CSF or G-CSF. The figure compares the proliferation (³H-thymidine incorporation) for cultures with (+) or without (−) IFNγ (50 ng/ml). Only those patients showing detectable proliferation (>1,000 cpm) with or without IFNγ were included in each comparison. Line denotes the median. IFNγ inhibited cytokine-dependent proliferation (P=0.0013 for IL1β, P<0.0001 for SCF, P=0.0398 for GM-CSF, P=0.0149 for G-CSF)