Considering the effect of CST1 on promoting the phosphorylation levels of MEK/1/2/ERK1/2 and EMT-related protein expression in our pilot study30, we explored the relationship between OXPHOS and the MEK/ERK signaling pathway in ESCC cells, by adding rotenone17 (a mitochondrial respiratory chain complex I inhibitor) to the ESCC cell lines KYSE410 and TE-1 with CST1 overexpression. Here, MAPK3 is linked to esophageal squamous cell carcinoma.