As the activation of Erk1/2 intracellular signaling can be associated with the affected cell’s response to cytotoxic agents, we then determined how the total and phosphorylated Erk1/2 (pT202/Y204; T185/Y187) forms are balanced in FaDu and SCC25 carcinoma cells before and after erastin treatment. This evidence concerns the gene MAPK3 and carcinoma.