NNMT and esophageal squamous cell carcinoma: Furthermore, a recent work showed that NNMT knockdown increases 5-FU sensitivity of esophageal squamous cell carcinoma cell line TE1 via suppressing Warburg effect, while overexpression of the enzyme in EC1 and Eca109 cells increased the 5-FU sensitivity, thus suggesting that NNMT can represent a potential therapeutic target to enhance the therapeutic activity of 5-FU [45].