To assess the functionality of EscS-HA mutant strains in a bacterial infection model, we examined the ability of EPEC ΔescS transformed with pEscSwt-HA, pEscSD46A-HA, pEscSD46K-HA, or pEscSK54A-HA to infect HeLa cells and to facilitate the translocation of effectors into the host cells. The gene discussed is NR2E3; the disease is bacterial infectious disease.