Cell-cycle analysis of PTPROt sense, antisense, and vector-only B-lymphoid transfectants. Two representative stable PTPROt sense, antisense, and vector-only DHL-4 B-lymphoid transfectants were cultured in 2% serum in the presence (right) or absence (left) of the microtubule-stablizing agent, nocodazole. When PTPROt sense, antisense and vector-only transfectants were grown in 2% serum in the absence of nocodazole, there were no significant differences in cell-cycle distribution (left panel). When PTPROt antisense or vector-only transfectants were treated with nocodazole, the G0/G1 portion of the cycle was greatly diminished and only 6% to 12% of the cells remained in G0/G1 (right panel). In marked contrast, ≈28% of nocodazole-treated PTPROt sense transfectants remained in G0/G1 (right panel).