Statistical analysis
Data were expressed as the means ± SEM and analyzed by performing
Student’s t-test. Significance levels were denoted as follows: *p
< 0.05, **p < 0.01, and ***p < 0.001. The
sample size is at least three and all experiments have been repeated at
least twice. In addition, the data were handled with Excel, PowerPoint,
and GraphPad Prism.