I am not sure which statistical procedure can and has to be applied here.

First, I will try to explain the experimental setup resulting in the data to be analyzed statistically. The data are levels of the cytokine IL-6 in the blood of mice treated with three different drugs and of untreated control mice. The mice were given one of the drugs at day 0 (or not given any drug in the case of the control mice). Then, blood was taken for determining IL-6 levels at day 5, day 7, day 10 and day 14.

*The question to be answered is: Are there any statistically significant differences in the IL-6 levels between treated mice and control mice at the individual time points?*

The time course itself is not of interest here, i.e. when IL-6 levels increase significantly.

So, would it be OK to use a one-way ANOVA + Dunnet's post-hoc test for the data from each individual time point (d5, d7, d10 and d14) to find out whether there are statistically significant differences between treatments and control? Or do I

**have to**use a two-way ANOVA because there are two factors here, time and drug treatment?