Collectively, these data suggested that circNF1 phosphorylated STAT3 via promoting the secretion of IL-6, thereby altering the enrichment level of p-STAT3 on the PD-L1 promoter, eventually driving PD-L1 transcription and accelerating the malignant progression of ESCC cells. This evidence concerns the gene STAT3 and esophageal squamous cell carcinoma.