Ma et al. (2017) reported that the levels of CD4+ and CD8+ T lymphocytes increased in spleens of chickens immunized with E. tenella 3-1E protein (Bessay et al., 1996). In this study, we obtained a similar result. The proportion of CD8+/CD3+ and CD4+/CD3+ T cells from spleens of experimental chickens showed a significant increase, which indicated a stimulation to the host that the EmROM3 induced for the production of cell-mediated immunity against coccidiosis and induction of T cell proliferation and differentiation. This evidence concerns the gene CD8A and coccidiosis.