Why WP5 and WP7 are separated? Why the in vitro and in vivo tests are not carried out in parallel?

Tests are not conducted in parallel because most of the partners are involved in two or three WP (WP5, WP6 and WP7) and it is difficult to perform the assays concomitantly. Moreover, WP6 will not investigate all the CNTs tested in WP5 and the results from WP5 and WP7 will help in selecting 4 out of the 7 CNTs for investigation in WP6.