PURA and esophageal squamous cell carcinoma: The MEST-expressing plasmid was cotransfected into ESCC cells with the plasmid expressing wild-type (WT) or mutant (Mut) PURA, and the results showed that the interaction between MEST and PURA was strongly inhibited when site#A, site#B or site#C was mutated, indicating the critical role of these amino acids in the MEST-PURA interaction (Fig. 4e, left panel).