To evaluate the involvement of CD44 in gastric cancer, we used the Tumour Immune Estimation Resource (TIMER), Gene Expression Profiling Interactive Analysis (GEPIA2), The Cancer Genome Atlas (TCGA), GEO and Human Protein Atlas platform (HPA) to comprehensively analyse whether CD44 exhibits different expression levels of mRNA and protein in gastric cancer. The gene discussed is CD44; the disease is cancer.