Changes in serum IL‐8 levels could monitor and predict clinical response of immune checkpoint blockade in melanoma and NSCLC patients.47 Early changes in serum IL‐8 levels (2‐4 weeks after treatment initiation) were strongly associated with response to checkpoint blockade treatment, with decreased IL‐8 levels in responders and increased IL‐8 levels upon cancer progression. Here, CXCL8 is linked to cancer.