KIR2DL4 and neoplasm: In addition, we failed to observe a net decrease in the immunological response against HLA-G-deficient tumors in vivo upon blockade of KIR2DL4, probably because KIR2DL4 and IFN-γ mediate extensive interplay between neoplastic and stromal cells in the tumor microenvironment, although the specific regulatory mechanisms remain unknown.