Co-transfection of pcDNA3.1-ZNF667-AS1 and pcDNA3.1-ZNF667 significantly decreased Eca109 and TE13 cells viability and invasiveness compared with solely pcDNA3.1-ZNF667-AS1 or pcDNA3.1-ZNF667 transfected cells, moreover, co-transfection of pcDNA3.1-ZNF667-AS1 and shRNA-ZNF667-3 partially reversed the intense reduction effect, indicating the synergistic effects of ZNF667-AS1 and ZNF667 on inhibiting esophageal cancer cells viability and invasion (Fig. 5h, i). This evidence concerns the gene PTGDR and esophageal cancer.