Based on limited published evidence, CBY3 plays a key role in sperm flagellar architecture by positioning the annulus, a septin-based ring structure that separates the midpiece from the principal piece. CBY3 interacts with CIBAR1 to stabilize the periannular membrane, preventing annulus migration and maintaining proper sperm motility. The gene is involved in spermatogenesis and flagellar organization. Recent transcriptomic profiling identified CBY3 as part of an 8-gene host signature discriminating drug-resistant tuberculosis from drug-susceptible tuberculosis 1, though the functional relevance in this context remains unclear.