With respect to the peripheral blood immunophenotype, no significant differences were observed in the lymphocyte subpopulations of adeno and squamous cell carcinoma, in comparison to a healthy control group significant differences were observed predominantly to squamous cell carcinoma patients with respect to CD3+/CD4+/CD8 + T cells, CD3+/CD4+/CD8+/FoxP3 + Treg cells, CD3+/CD56+/CD94+/NKG2D + NKT cells and CD3-/CD56+/CD69 + NK cells (Supplementary Fig. 1A–O). Here, KLRK1 is linked to squamous cell carcinoma.