CD4 and neoplasm: FNA revealed an intratumoral expansion of neutrophils with an immunosuppressive phenotype that were increased in non-responders to immunotherapy (mean 50.2% <i>vs.</i> 25.5% in responders, <i>p =</i> 0.015) and correlated inversely with CD8<sup>+</sup>T<sub>RM</sub> and CD4<sup>+</sup>T<sub>RM</sub> frequencies (r = 0.6, <i>p =</i> 0.001).<h4>Conclusion</h4>FNA are suitable for rapid, comprehensive sampling of HCC prior to and during immunotherapy, revealing features of the tissue-resident tumour immune niche that cannot be predicted from blood.