IL-21 is a broad negative regulator of IgE class switch recombination in mouse and human B cells.

Though the magnitude of the IgE response with selective Tfh cell deficiency in IL-21 (group 4) was somewhat less pronounced than with the 100% Il21 −/− (group 5), overall, the group 4 response was clearly significantly elevated compared with the control groups ( Fig. 4 B ), particularly when considering the frequency of IgE + PCs.

also in 180 other papers

We observed a trend toward decreased frequencies of IgG4 + cells when IL-21 was added, though this did not reach statistical significance.

also in 111,027 other papers