To map the spatial distribution and functional states of tumour antigen-specific CD8+ T cells in the tdLN, we performed 3D tissue imaging12 of optically cleared day 8 tdLN slices (around 300 μm thickness, comprising about 25–30% of the whole tdLN volume) derived from mice adoptively transferred with a physiological frequency of naive OT-I precursors (500 cells)13 and intradermally implanted with an ovalbumin-expressing KrasG12D/+Trp53−/− lung adenocarcinoma line14 (KP-OVA). This evidence concerns the gene CD8A and neoplasm.