Using the Western blot method, we evaluated the changes in the total content of the active forms of JNK, namely phospho-(Thr183/Tyr185)-SAPK/JNK 54 kDa and 46 kDa (pJNK) and active phospho-(Ser133)-CREB (pCREB), as well as in the level of the MMP-9 and c-Fos proteins in the subcortical structures and cortex of rats at 24 h after the onset of occlusion in the groups of animals with “ischemia–reperfusion” (IR) relative to the animals of the group with “sham operation” (SH), as well as under the effect of Semax in ischemia (IS) relative to the IR group. The gene discussed is FOS; the disease is ischemia.