JAK2 and gastric cancer: In contrast, the addition of an IL-17a neutralizing antibody or the JAK2 protein tyrosine kinase inhibitor AG490 to the co-culture system significantly reversed the TANs-mediated phosphorylation of JAK2 (P < 0.05 and P < 0.05 in MKN45 and MKN74 cells, respectively) and STAT3 (P < 0.05 and P < 0.05 in MKN45 and MKN74 cells, respectively) and had no effect on the expression of JAK2 and STAT3 in GC cells (MKN45 and MKN74) (Fig. 5a and b).