MAPK9 and congenital secretory chloride diarrhea 1: The first step to characterize the role of JNK2 in CLD was to select the most potent siRNA sequence for the knockdown of Jnk2. In order to achieve the highest efficiency in blocking Jnk2, we first designed 12 different sequences for the siJnk2-LNP that target the mRNA via different binding regions (Fig. 1a).