Induction of the hypoxia-inducible factor-1α (HIF-1α) plays a role in the maintenance of MCL-1 during the initial stages of chlamydial infection, and likely involves the ERK pathway, as pharmacologically inactivating ERK signaling in infected cells with the MEK-1 inhibitor UO126 could prevent HIF-1α from degradation. This evidence concerns the gene HIF1A and chlamydia trachomatis infectious disease.