MAPK8 and Alzheimer disease: The phosphorylated forms and ratios for p-ERK1/2/total ERK1/2, p-JNK/total JNK, and p-p38/total p38 were selectively increased in AD-treated subjects although did not reach statistical significance in the case of p-ERK1/2/total ERK1/2 ratio (Fig. 2b, d, f).