To further explore this association during T cell activation in vitro, we stimulated peripheral blood mononuclear cells (PBMCs) derived from lung cancer patients with anti‐CD3 and anti‐CD28 antibodies and observed that levels of CD62L (encoded by SELL) and CCR7 expression in activated CD8+ T cells were positively correlated with the proportion of monocytes (Figure 1b; Figure S1b,c, Supporting Information). Here, SELL is linked to lung cancer.