MAPK8 and persistent truncus arteriosus: However, this increase in JNK activation was not observed in LZM hearts post-TAC (0.5±0.1 ADUs in LZM sham hearts versus 1.3±0.2 ADUs in LZM 48-hour TAC hearts, P=NS LZM sham versus LZM TAC; P<0.001 LZM TAC versus WT TAC) (Figure 6A).