MAPK3 and nasopharyngeal carcinoma: Therefore we investigated whether pY772-EphA2 phosphorylates and activates Erk-1/2 via Shp2 in the NPC cells and observed that Shp2 overexpression restored p-Erk-1/2 levels in the NPC cells expressing EphA2-YA (Fig. 3b); either Shp2 knockdown or Shp2 inhibitor SHP099 dramatically decreased p-Erk-1/2 levels in the NPC cells expressing EphA2-WT (Fig. 3c, d).