Secondly, statistical analysis showed that the positive predictive values of G-17 level and ALDH1 level in gastric juice for the diagnosis of GC were 80% and 63.3%, negative predictive values were 67.7% and 59.4%, the agreement rates were 70.6% and 60.3%, and Kappa values were 0.371 and 0.172, respectively. Here, ALDH1A1 is linked to gastric cancer.