The challenge ahead is formidable, but we may be approaching the objective and indeed, in some areas of medicine, such as haematopoietic stem cell transplantation and treatment of hepatitis, KIR typing is entering the clinical practice and may improve patient outcome (Foley et al. 2014; Vidal-Castineira et al. 2014; Stelma et al. 2016). The gene discussed is KIR3DL1; the disease is Hepatitis.