Although IL-33 had no effects on the proliferation capability of SGC7901 and MKN45 cells (data not shown), the addition of exogenous IL-33 or co-culture with CAFs led to increased migration and invasion of both SGC7901 and MKN45 cells, while anti-IL-33 antibody attenuated these stimulatory effects of CAFs on GC cells (Fig. 2a–d). This evidence concerns the gene IL33 and gastric cancer.