IL6 and cancer: NF‐κB has been shown to collaborate with p38 MAPK to induce IL‐6 expression.32 Also, p38 MAPK is one of the signalling mediators downstream of activin A.33 We found that coinciding with reduced pNF‐κB and IL‐6 levels, interference with activin A signalling reduced the level of phospho‐p38 in the cancer cells (Figure3I).