The expression of genes of all tested cytokines and related transcription factors (STAT4, INF-γ, GATA3, STAT6, IL-10, IL-13, SOCS3) was detected in three groups of dogs—in dogs with mild/moderate and severe babesiosis (groups Babesia 1 and Babesia 2) and in dogs co-infected with B. canis and D. repens (Figs. 1, 2, 3). The gene discussed is STAT6; the disease is babesiosis.