The inability of the IL-15-based transcriptomic protection signature to distinguish protection outcomes following HPAI challenge indicated that unlike both RhCMV/SIV- and dd CyCMV/SIV-mediated protection against SIV replication29,36, CyCMV/Flu-mediated protection against lethal HPAI infection did not depend upon MHC-E-restricted CD8 + T cells and the IL-15 signaling pathway. This evidence concerns the gene IL15 and infection.