JUN and cancer: Because TOPK signalling pathways are involved in cell cycle, apoptosis, and cancer cell growth, we determined the effects of acetylshikonin on the expression of phosphorylated TOPK (Thr9), phosphorylated ERK (Thr202/Tyr204), phosphorylated RSK (Ser380), and phosphorylated c‐Jun (Ser73) as well as on the transcriptional activity of NF‐κB (Figure 4).