Immune checkpoint inhibitors, such as pembrolizumab, nivolumab, avelumab, atezolizumab and durvalumab, are not only approved for use in patients with tumours that express PD-L1 but are also indicated for certain solid tumour types without the need to assess PD-L1 expression38–43,49–54. The gene discussed is CD274; the disease is neoplasm.