Moreover, BTG2 over‐expression inhibits interleukin‐6 (IL‐6) expression through downregulation in the STAT3 pathway, as well as inhibiting reactive oxygen species (ROS) generation in the JAK2‐STAT3 signalling pathway (Quy et al., 2013); thus it has a negative effect on cancer cell growth. This evidence concerns the gene JAK2 and cancer.