genetic correlation of hla alleles and kir allotypes, a firm conclusion has not yet been drawn as to what combination provides decreased hiv and aids susceptibility. nk cells can impose immune pressure on hiv, which had previously been described only for t cells and antibodies. hiv mutates to avoid nk cell detection. tissue-resident nk cells most of our current knowledge is derived from investigations of mouse splenic and human peripheral blood nk cells. however, in recent years tissue-resident nk cell populations have been described. these tissue-resident nk cells share transcriptional similarity to tissue-resident memory t cells described previously. however, tissue-resident nk cells are not necessarily of the memory phenotype, and in fact, majority of the tissue-resident nk cells functionally immature. these specialized nk-cell subsets can play a role in organ homeostasis. for example, nk cells are enriched in the human liver with a specific phenotype and take part in the control of liver fibrosis. tissue-resident nk cells have also been identified in sites like bone marrow, spleen and more recently, in lung, intestines and lymph nodes. in these sites, tissue-resident nk cells may act as reservoir for maintaining immature nk cells in humans throughout life. adaptive nk cells against leukemia targets natural killer cells are being investigated as an emerging treatment for patients with acute myeloid leukemia (aml), and cytokine-induced memory-like nk cells have shown promise with their enhanced antileukemia functionality. it has been shown that this kind of nk cell has enhanced interferon-γ production and cytotoxicity against leukemia cell lines and primary aml blasts in patients. during a phase 1 clinical trial, five out of nine patients exhibited clinical responses to the treatment, and four patients experienced a complete remission, which suggests that these nk cells have major potential as a successful translational immunotherapy approach for patients with aml in the future.