ACKR1 encodes a transmembrane glycoprotein that is a receptor for pro-inflammatory cytokines and malaria parasites.7 The recessive allele for rs2814778, which is a point mutation in the promoter region, results in a lack of expression of ACKR1 protein on red blood cells20 and thus a red blood cell membrane antigen phenotype termed Duffy null or Fy(a-b-). Here, ACKR1 is linked to malaria.