Fig. 2

Thieno[2,3-b]pyridines derivatives inhibit cell proliferation. Relative thymidine incorporation of a panel of breast cancer cell lines was measured after 3 days treatment of derivatives 1–6. IC₅₀ values (50 % inhibition of growth) are shown in nanomolar (nM). IC₅₀ value was not reached for the concentration tested for derivative 5 in T47D cell line