For instance, cAMP inhibition of LPS-induced iNOS expression in C6 glioma cells was via suppressing the phosphorylation of p38-MAPK, while in RAW264.7 macrophages LPS-induced p38-MAPK phosphorylation was not affected by cAMP which, on the contrary, up-regulated iNOS expression [34]. Here, NOS2 is linked to central nervous system cancer.