Our findings suggest that: [i] inhibition of Tiam1-Rac1-Nox2 pathway (NSC23766) significantly attenuates hyperglycemia-induced p38 MAP kinase in the retina and its capillary cells and [ii] 2-BP, an irreversible inhibitor of S-acyltransferase, markedly attenuates Rac1-Nox2-p38 MAP kinase cascade. The gene discussed is CYBB; the disease is Hyperglycemia.