In the present study, we demonstrated that TSA resulted in the activation of ERK1/2 in ESCC cells, whereas inhibition of ERK1/2 activity via application of the MEK1/2 inhibitor U0126 prevented TSA‐induced ESCC migration, EMT, and upregulation of Slug levels, thus suggesting the ERK1/2‐slug pathway as a critical regulator of EMT in TSA‐induced ESCC migration. Here, MAPK3 is linked to esophageal squamous cell carcinoma.