In patients with gastric cancer, lncRNA AA174084 is in a downregulated state, so it can be used as a marker for the early diagnosis of gastric cancer;128 in patients with colorectal cancer, if lncRNA CCAT1 and CCAT2 are highly expressed, it means that the survival rate and recurrence rate of the disease are low, so it can also be used as a clinical examination test marker.129. The gene discussed is CCAT2; the disease is gastric cancer.