MAPK14 and intervertebral disk degenerative disorder: Figure 1C shows that expression of p38α, β and δ can be detected but not p38γ. We next evaluated the expression pattern of p38 isoforms and phosphorylated p38 in NP extracts from 14 graded IDD patients. In comparison to normal NP tissues (grade II), the expression of p38α, β and p-p38 were remarkably increased in diseased tissues (Fig. 1D,F). And p38δ were only detected in half of IDD sample. The expression of p38α, β and p-p38 tended to increase with worsening of the disease (Fig. 1D,F). Whereas all of 14 NP tissue displayed very low or almost no p38γ expression (Fig. 1D,F).