Our findings on KIR genetic diversity and frequencies of KIR-HLA pairs in the Medellin population are likely to shed light on the formation of KIR repertoires and the potential implications in processes of NK cell education and function, and their impact in immune response against viral infections, anti-tumor response or transplant outcomes, however these associations remain unexplored in Colombia. This evidence concerns the gene KIR3DL1 and neoplasm.