To further explore how neutrophils enhance the metastatic ability of tumour cells, the authors pre-treated for 24 h tumour cells with cytokines such as Il1-β or Interleukin 6 (Il-6), which are often secreted by neutrophils, and found out that inoculation of cytokine-treated tumour cells on animals led to more aggressive metastases and faster demise. The gene discussed is IL6; the disease is neoplasm.