NK cell activation against cancer cells is triggered by diverse activating receptors that are often downregulated as a mechanism of systemic NK cell dysfunction in various cancers.[2, 55] Thus, we assessed the expression of diverse activating receptors on NK cells and found a slight decrease but no significant difference in the expression of NKG2D, 2B4, NKp30, NKp46, or DNAM‐1 on NK cells between the 2 groups (Figure S16c,d, Supporting Information). Here, CD226 is linked to cancer.