JAK2 and cancer: Epidermal growth factor (EGF) signalling is well known to support the migration and invasion of OS cells, as well as those of many other cancers,41 which we determined by examining the downstream JAK1/2‐STAT3 signalling pathway.42 As shown in Figure 5E, IL‐6‐induced phosphorylated JAK1, JAK2 and STAT3 up‐regulation activated the JAK1/2‐STAT3 signalling pathway.