Although the GF*GF index for the combination of KIR3DL1 with HLA-Bw4 was significantly higher in malaria high-endemic than in malaria low-endemic populations (P = 0.0042), this is most likely due to a significant negative correlation between HLA-C1 and HLA-Bw4 gene frequencies in these 29 populations (r = −0.42, P = 0.023, Figure 4), which is explained by strong linkage disequilibrium between HLA-C and HLA-B[39]. Here, HLA-C is linked to malaria.