Cell growth following induction of Ik6.

Growth of cells from 32D/TREx/Ik6 clones (clone 7, 11, and 14) and 32D/TREx/empty. Numbers of viable cells were determined by trypan blue dye exclusion. All 3 Ik6 clones grew well in an IL-3–deprived culture medium in the presence of tetracycline (closed symbols; Ik6 on), but not in its absence (open symbols; Ik6 off). No growth of the empty clone was noted in either medium. (B) Western blot analysis before (0 hour) and after (24 hours) induction of Ik6 in cells from 32D/TREx/Ik6 clone 11. Note Ik6 induction in cells cultured for 24 hours in IL-3–deprived medium with tetracycline (on).