Reconstitution of wild-type SOCS1 causes cell death in cHL lines carrying concurrent mutations of SOCS1 and STAT genes. (Top) Western blot analysis of phosphoSTAT6 after lentiviral transduction of myc-tagged SOCS1 in 4 cHL cell lines (1 representative experiment per cell line is shown, of 2-4 independently performed, that gave reproducible results); β-tubulin is used as loading control, and the normalized levels of total and phosphoSTAT6, quantified by densitometry, are shown below the respective blots. (Bottom) Raw percentage of live cells (based on forward/side scatter parameters by flow cytometry) over time (day 0 = 48 hours after SOCS1 transduction). Error bars (standard error of the mean) refer to at least 3 independent experiments per cell line per time point (except HDLM2/d 1, n = 2 replicates). The induction of cell death on SOCS1 transduction in HDLM2 and L1236 is statistically significant (P values < .05 for each cell line based on 2-way ANOVA). Supplemental Figure 14 shows the same data after normalizing the percentage of live cells in the SOCS1-vector sample to the corresponding empty-vector control sample (set at 100%).