CD99 and neoplasm: Linking the scRNA‐seq data of individual pLCOs with their responses to anti‐PD‐1 (αPD‐1) immune checkpoint blockade (ICB) allows to confirm the central role of CD8+ T cells in anti‐tumor immunity, to identify potential tumor‐reactive T cells with a set of 10 genes, and to unravel the factors regulating T cell activity, including CD99 gene.