KIR genotype analysis of patients with acute ischemic stroke in comparison with subjects without ischemic stroke showed a higher frequency of 2DL3 (74.1% vs 42.4% p < 0.0001), 2DL5B (33.6% vs 18.8%; p = 0.03), 2DS2 (37.9% vs 16.6%; p = 0.003), 2DS4 (41.3 vs 16.6; p < 0.0001), and 3DP1 (14.6% vs 0; p < 0.0001) KIR genes (see Table 2 and Fig. 1) and a lower frequency of 3DL1 (67.2% vs 89.3%; p < 0.0001), 3DL2 (67.2% vs 100%; p < 0.0001), 3DL3 (62.9% vs 100%; p < 0.0001), 2DS5 (14.6% vs 51.5%; p < 0.0001), and 2DP1 (77.5% vs 100%) KIR genes in comparison with subjects without stroke. This evidence concerns the gene KIR3DL1 and ischemic stroke.