VAMP3 and infection: Knockdown of either VAMP3 or VAMP4 with siRNA prior to infection with C. trachomatis serovar L2 results in a decreased circumference of chlamydial inclusions (Fig. S2B), and our data revealed a statistically significant reduction in infectious progeny in single VAMP4 knockdown, but not VAMP3 knockdown or a double VAMP3/VAMP4 knockdown, compared to nontargeting control siRNA (Fig. S2C).