JAK1 and neoplasm: Inflammatory cytokines and signalling pathways are well known to play pivotal roles in enhancing tumour metastasis and drug resistance.53, 54 IL‐6 secreted in the tumour microenvironment activates the JAK/STAT3 signalling pathway, favouring tumour growth and metastasis.55, 56 In determining the potential mechanism, we found that Tan I blocked IL‐6‐induced JAK1/2 and STAT3 activation and down‐regulated p‐JAK1/2 and STAT3 protein levels (Figure 5E‐G).