Figure 2.

Comparison of the proliferative response of abl-deficient and control lines to IL-7. [³H]Thymidine incorporation as an indicator of cellular proliferation is plotted against rising IL-7 concentrations. Cells were cultured for 72 h with recombinant IL-7 and pulse labeled with [³H]thymidine during the last 6 h of culture (see Materials and Methods). The IL-7 dose-response curves of the abl-deficient clones AN-1, AN-2, and AN-3 and the control clones AP-1, AP-2, and AP-3 are indistinguishable.