KIR3DL1 and classic Hodgkin lymphoma: The analysis of the combinations of KIR genes and their specific ligands showed a significantly higher frequency of KIR3DS1 and KIR3DL1 when combined with the absence of their specific ligand HLA-Bw4 in cHL patients (15.5 vs. 6.3 %, p = 0.006 and 33.3 vs. 21.3 %, p = 0.013, respectively).