There is strong evidence that genotype for IFNL4-ΔG/TT may play a role in other infections [9, 10] and, given that expression of the interferon lambda receptor (IFN-λR1) is largely restricted to cells of epithelial origin [11, 12], it is plausible that this genetic variant could affect viral infections of the epithelium. This evidence concerns the gene IFNL4 and viral infectious disease.