To this end, we investigated the expression patterns of immune molecules CD4 and CD8b, cytokines (IFN-γ, IL-6, and IL-10), and TLRs (TLR2–10, and TLR13) mRNAs in a larger number of captive koala populations (n = 37), based on KoRV subtype profiles, including KoRV-A, KoRV-A+B, KoRV-A+B+D, KoRV-A+B+F, KoRV-A+D+F, KoRV-A+B+C+D, KoRV-A+B+D+F, and KoRV-A+B+C+D+F infections [31]. This evidence concerns the gene CD4 and infection.