STAT3 is cleaved by calpain in vivo and in vitro.

(A,B) Methods were the same as those described in the legends for Figures 1A and 1B, respectively, except that the blots were probed by using anti-STAT3 antibodies. (C) Cleavage of STAT3 during platelet aggregation. Methods were the same as those described in the legend for Figure 1C except that STAT3 was recognized by the anti-STAT3 MoAb as in Figure 2A.