The function of Natural Killer (NK) cells is typically predicated upon the ‘missing self’ hypothesis, where an absence of Human Leukocyte Antigen (HLA) class I expression on target cells prevents signalling through inhibitory Killer cell Immunoglobulin-like Receptors (KIR) to allow for NK cell activation. However, the vast allelic polymorphism found in both HLA and KIR can impact their strength of interaction and their subsequent capacity to inhibit NK cells. Meanwhile, HLA loss itself is not always complete, can be allotype specific and can occur over time. To investigate the sensitivity of different allotypic KIR/HLA pairings to reduced HLA levels, the variable capacity of KIR3DL1 allotypes to bind HLA-Bw4 molecules was first demonstrated using HLA tetramers. When next encountering targets with reduced HLA-Bw4 levels, as opposed to HLA null targets, an inverse relationship was observed where weaker KIR3DL1/HLA-Bw4 interactions allowed for more robust responses. Moreover, when HLA-Bw4 loss was induced over time through the expression of viral evasins, reporter cell assays demonstrated stronger KIR3DL1/HLA-Bw4 pairs to retain HLA recognition longer than those with weaker pairings. Loss of HLA-C2 molecules from the cell surface in the presence of viral evasins occurred more rapidly than HLA-Bw4 allotypes, however KIR2DL1 retained recognition of HLA-C2 even at low levels. Although further combining empirical measures of binding strength with the capacity of KIR3DL1⁺ NK cells to respond to HLA-deficient targets showed high affinity interactions to drive education, lower affinity interactions may instead be retained in the population to increase the capacity of NK cells to sense more subtle changes in HLA expression. Therefore, disease outcomes may vary depending on the extent or nature of HLA loss, and the importance of sensing such changes in HLA levels for resolution.