In the present study, we found that the mRNA expression of PYCR1 was significantly up-regulated in EC tissues via GEPIA (Gene Expression Profiling Interactive Analysis; http://gepia.cancer-pku.cn/) database analysis, which was further confirmed in the detection of our ESCC tissue samples, suggesting that PYCR1-mediated proline metabolism disorders may be involved in ESCC progression. Here, PYCR1 is linked to esophageal squamous cell carcinoma.