JAK2 and gastric cancer: The phosphorylated STAT3 enters the cell nucleus in the form of a dimer and regulates the expression of target genes, which promotes cell growth and causes immune escape.[17] As for the relation between JAK2‐STAT3 and cancers, several studies reported that abnormal activation of JAK2‐STAT3 pathway results in disease progression and poor survivals of patients with colon and gastric cancers.[18, 19]