CXADR and neoplasm: The potential significance of p38 MAPK in chemical-elicited CAR activation was also indirectly supported by the facts that phenobarbital-mediated induction of CYP2B1 was stimulated in the liver of diabetic rats where p38 MAPK was activated by the disease itself (Yoshida et al., 1996); while CYP induction by phenobarbital was attenuated in tumor-bearing rats where p38 MAPK was down-regulated (Numazawa et al., 2005).