However, the discovery of biased usage of the IG heavy chain variable (IGHV) germline gene IGHV1-69 in anti-hemagglutinin stem-directed broadly neutralizing Abs (HV1-69-sBnAbs) and the finding that only the heavy chain makes contact with hydrophobic HA stem2 has provided a unique opportunity to define the molecular features of anti-influenza BnAbs and simplify immunogenetic studies to understand the contribution of allelic variation at the IGHV1-69 locus to the anti-influenza sBnAb response. The gene discussed is DDX41; the disease is influenza.