MAPK8 and crescentic glomerulonephritis: Using Ask1 gene‐deficient mice, we have shown that activation of p38 MAPK, and to a lesser extent JNK, is dependent upon ASK1 in the obstructed kidney, while administration of a highly selective ASK1 inhibitor (GS‐444217) in experimental diabetic kidney disease also suppressed p38 and JNK activation.23, 24 However, it is unknown whether p38 and/or JNK activation depends upon ASK1 in the aggressive renal inflammation seen in crescentic glomerulonephritis.