“…We have previously demonstrated that IL-21-induced apoptosis is dependent on STAT3, cMYC, and Bax, and is independent of STAT1 in DLBCL and MCL cell lines. 32,35 Treatment with aCD20-IL-21 fusokine resulted in upregulation of pSTAT1, pSTAT3, and pSTAT5, similar to IL-21 alone, and was not observed in cells treated with the parent aCD20-IgG1 Ab ( Figure 3A). Furthermore, we also found upregulation in cMyc, BAX, and downregulation of the antiapoptotic proteins BCL-xL and Bcl-2, which was more pronounced in the fusokine-treated cells compared with native IL-21 ( Figure 3B; supplemental Figure 4A).…”