SB 202190 is a highly selective, potent, cell-permeable inhibitor of p38 MAP kinases, inhibiting p38α (SAPK2A, MAPK14) and p38β (SAPK2B, MAPK11) with IC₅₀ values of 50 and 100 nM, respectively. At higher concentrations (10 µM), SB 202190 displays negligible effects on several other kinases including other MAP kinases (ERKs, JNKs).