However, after 44 h of infection (late developmental cycle), there is a statistically and biologically significant ~10-fold decrease in infectious progeny obtained from Chlamydia grown in syntaxin 10 siRNA-treated cells (4.93 × 106 ± 4.85 × 105) vs. control cells (3.75 × 107 ± 1.62 × 106). This evidence concerns the gene STX10 and infection.