Summarizing the results of the study of EV size and CD9 occurrence in the samples from GC patients and healthy subjects, the following conclusions can be drawn: (1) EVs from gastric cancer patients were significantly larger compared to those from healthy controls; (2) CD9(+) EVs were consistently larger than CD9(−) EVs; and (3) the distribution of CD9(+) and CD9(−) EVs differed markedly between the two groups, with control samples predominantly consisting of CD9(−) EVs, while GC samples exhibited a more balanced distribution. The gene discussed is CD9; the disease is gastric cancer.