Host tropism and zoonotic prediction between the Egyptian HPAIV H5N1 and LPAIV H9N2 strains. (A) The host tropism signatures of proteins from both parent strains depict the individual host tropism predictions of 11 viral proteins (HA, M1, M2, NA, NP, NS1, NS2, PA, PB1, PB1-F2, and PB2), determined using deduced protein sequences. The intensity of the color represents the confidence in the avian or human tropism prediction by the individual protein prediction models. Both parent strains carry a typical avian tropism signature with 11 avian protein tropisms. (B) The signatures were next used for a second layer of machine learning prediction for classification of avian (A), human (H), or zoonotic (Z) strains, where both strains were predicted to show low zoonotic risks.