a slight trendP = 0.0173
A slight trend was observed indicating a stronger increase using longer incubation periods (DGJ: 1.9-fold (5 days) vs. 2.3-fold (14 days), P = 0.0173; BTZ: 2.1-fold (5 days) vs. 3.0-fold (14 days), P = 0.0921, unpaired two-sample t -test).