MAPK8 and amyotrophic lateral sclerosis: In our study, although the expressions of p38 MAPK, p44/42 MAPK and JNK were unaltered by ALS treatment (Fig. 4A), p-p38 MAPK, p-JNK and p-p44/42 MAPK level were significantly up-regulated and remained elevated till 24 h of ALS exposure (Fig. 4B) (P < 0.05).