The invention provides an application of a biomarker in predicting a gastric
cancer immunotherapy effect and a related product. The biomarker is clustered
protein. The gastric
cancer treatment effect of the anti-PD-1
antibody can be predicted by detecting the expression level of
clusterin or mRNA thereof in a gastric
cancer tumor
cell or
tumor tissue sample. Furthermore, by inhibiting the expression level of
clusterin, the gastric
cancer treatment effect of the anti-PD-1
antibody can be improved. A new biomarker cluster
protein is provided for predicting the gastric
cancer treatment effect, and the cluster
protein can be used as a novel target spot of the gastric cancer, so that a new direction is provided for screening drugs for treating the gastric cancer and treating the gastric cancer.