“…This hurdle, known as checkpoint blockade, can be overcome by the release of proinflammatory cytokines (Noy & Pollard, ), such as TNF‐α, IFN‐γ which induces the activation of antitumoral macrophages, or mainly, by using antibodies blocking immune‐suppressor molecules present in activated CD8 + T cells such as PD‐1 and CTL‐4 (Havel, Chowell, & Chan, ; Ribas & Wolchok, ). Note that checkpoint inhibitor (CPI) blockade using antibodies, principally anti‐PD‐1, anti‐PD‐1 ligand (PD‐L1) and anti‐CTLA‐4, have been shown to be the most effective treatments in many different tumours including melanoma, non‐small cell lung cancer, kidney cancer, bladder cancer, head and neck cancers, Hodgkin lymphoma or Merkel cell carcinoma (Havel et al, ; Ribas & Wolchok, ). Most patients, however, (~75%) do not respond and there is usual appearance of tumours resistance to CPI treatments (Friedrich et al, ; Kim, Herbst, & Chen, ).…”