CD79A and esophageal squamous cell carcinoma: The mean value of P. gingivalis IgA in early stage ESCC was lower (32.08 EU) than that of late stage ESCC (41.76 EU) without statistical significance (P = 0.29), whereas the mean IgG value was marginally higher in early stage ESCC (114.35 EU vs. 113.62 EU, P = 0.058).